Introduce support for new URL Cleanup tests that can check:

- Guessed type of relationship for a given URL and entity type
- Cleanup of a given URL
- Guessed type of relationship after cleanup
- Validation of an URL (after cleanup) for every entity types

Tests specification is programmatically checked, to a certain
extent, in order to prevent misleading results.

Supported self-explanatory test properties:

- `input_url`: mandatory
- `input_entity_type`: required by `expected_relationship_type`
- `expected_relationship_type`: optional,
- `expected_clean_url`: optional
- `input_relationship_type`: optional to `only_valid_entity_types`
- `only_valid_entity_types`: optional, require
                             either `expected_relationship_type`
                             or `input_relationship_type`

Allowed combinations of test properties:

- `input_url
      input_entity_type expected_relationship_type`
- `input_url
     [input_entity_type expected_relationship_type]
         expected_clean_url`
- `input_url
      input_entity_type expected_relationship_type
        [expected_clean_url]
            only_valid_entity_types`
- `input_url
     [input_entity_type expected_relationship_type]
        [expected_clean_url]
            input_relationship_type
               only_valid_entity_types`

Usage (beyond equality tests) of test properties:

- Match is performed w.r.t. `input_url` and `input_entity_type`
- Clean is performed w.r.t. `input_url`
- Validation is performed with respect to:
  - `input_relationship_type`, else `expected_relationship_type`
  - `expected_clean_url`, else actual clean URL

Additional note for type-free and inappropriate URLs:

- `expected_relationship_type` can be set to `undefined`
- `only_valid_entity_types` can be set to `[]`

As examples, two tests are provided within this initial commit:

- AllMusic URL for release-groutp relationship replaces both
  'Guess type' and 'Cleanup' tests and extends to validation test.
- ResidentAdvisor review URL for release-group replaces former
  'Guess type' test and extend to invalidation test (MBS-8148).

To conclude with, these new tests are streamed as TAP subtests.
Subtests labels are not redundant with assertions labels.

Note that the current Jenkins setup (without Jenkins TAP plug-in) at
ci.metabrainz.org only displays assertions labels in "Test Result",
use "View as plain text" for full-featured TAP stream (including
actual and expected values in the case of assertion failure).

'Guess type' tests conversion is straithforward:
- 1st items are converted to `input_entity_type` properties
- 2nd items are converted to `input_url` properties
- 3rd items are converted to `expected_relationship_type` properties

'Cleanup' tests are not that easily converted:
- 1st items are converted to `input_url` properties
- 2nd items are converted to `expected_clean_url` properties
- 3rd items are converted to `input_entity_type` properties
  and are used to deduce the `expected_relationship_type` properties

  However, these lattest optional 3rd items of 'Cleanup' tests were
  actually not reliable.  Because they were used for display only,
  they were not checked and sometimes erroneous.  Thus the resulting
  `input_entity_type` and `expected_relationship_type` properties
  can be misleading or erroneous too.  All of these uncertainties
  and errors are marked with FIXME comments that are addressed and
  removed in the following commits of this pull request.

Tests are reordered by target website, and grouped below its name in
comment.  All other comments have been removed since they were
redundant with either test content or issue tracker.

See preceding commit for comprehensive examples of test conversion.

Additionally, this conversion of all tests in one commit allows:
- to merge tests together (removing 78 test entries)
- to check and fix the 3rd item (entity type) of 'Cleanup' tests
- to automatically verify type consistency of cleaned-up URLs.

Merges, checks and fixes take place in the eight following commits.

Prior to this pull request, 'Type guess' tests and 'Cleanup' tests
were distinct although they were sometimes based on the same URLs.

Tests using the same `input_url` (and `input_entity_type` if any)
are merged into one.

(This actually removes 20 tests.)

Prior to this pull request, clean URL was not checked to match the
same relationship type as the input URL.  This is now auto-checked.

Match-only tests using the same `input_url` as the
`expected_clean_url` of another test are merged into it.

(This actually removes 47 tests.)

Prior to this pull request, entity type was used for display only.

Now, it is used to check the auto-selected relationship type.

This patch checks that no relationship type is auto-selected.

Prior to this pull request, entity type was used for display only.
For some cleanup tests, it was wrongly set to the `streamingmusic`
relationship type.

Now that both types are available to cleanup tests as well, this
patch fixes both entity and relationship types to these tests.

Previously, this test was duplicated (it goes back to MBS-6432) and
erroneously set to nonexistent `lyrics.release` link type (which
silently passed the test function prior to this pull request).

This patch deduplicates and updates it to `lyrics.release_group`.

These entity types have been checked since.

Prior to this pull request, entity type was used for display only.
For these two tests, it was erroneously set to another entity type.

This patch just fixes consistency of these tests.  Adding validation
tests would require to fix the URL cleanup component first.

Prior to this pull request, clean URL was not checked to match the
same relationship type as the input URL.  This is now auto-checked.

This patch removes and merges some tests which are redundant by
their entity type, relationship type, and input/clean URL patterns,
all at once.

(This actually removes 10 tests.)

These comes as additional examples for MBS-6378 and MBS-5736.

This commit ends the pull request that adresses these issues.