[BUGFIX] Use full url to the distribution images in XML file

See merge request !658

[BUGFIX] Change field to "em_category"

See merge request !657

Use service to check and update static JSON file

See merge request !652

[CI] Add XDEBUG_MODE=coverage to composer test:unit to have support for xdebug 3.0.x

See merge request !655

Merge branch '516-add-information-on-uploading-extension-version-without-composer-json' into 'develop'

[TASK] Add information on uploading extension version without composer.json

Closes #516

See merge request !654

[FEATURE] Add Middleware for composer manifest generation

Closes #515

See merge request !653

Resolve "Minimum dependencies not displayed correctly"

Closes #500

See merge request !650

[BUGFIX] Use plain text format for version notification email

Closes #511

See merge request !648

Merge branch 'develop' of ssh://gitlab.typo3.org:2222/services/t3o-sites/extensions.typo3.org/ter into 511-ter-rest-api-generates-notification-emails-with-no-linebreaks

The file extension of NewVersionNotify is changed from
`.html` to `.txt`, since it's a plain text template. This allows
to use the same template together with FluidEmail for both,
the REST API and the TER API.

[TASK] Add last sync info to charts footer and change orange color

See merge request !647

Resolve "Add anchors for each version in version history for direct link"

Closes #510

See merge request !646

Due to color, see services/t3o-sites/common/t3olayout#643

Relates: #509

[TEST] Improve tests for LTSVersionServer

See merge request !609

[TASK] Improve tests

See merge request !630