Feature: #86457 - TCA Type Slug adds a prepending slash

See forge#86457

Description

The new TCA type slug field now hard-codes a slash as a prefix for all pages, as this is mandatory for URL resolving and ensuring a uniqueness within a site.

However, for slug types within regular records, it is not necessary to do so, therefore the slash is never prepended on a "regular" slug field.

If - in some special cases - the "slug" field should contain a slash (due to e.g. nested categories with human readable url path segments), a new option prependSlash is added to TCA type slug.

Impact

Third-party extensions using the slug field now receive a slug value without a slash, and can use this as a regular - sanitized - slug field. It is however recommended to use the uniqueInPid eval option to ensure uniqueness.

If a nested record structure is given, it is recommended to use the new option prependSlash by setting it to true.

'type' => 'slug',
'config' => [
    'generatorOptions' => [
        'fields' => ['title'],
    ]
    'fallbackCharacter' => '-',
    'prependSlash' => true,
    'eval' => 'uniqueInPid'
]