Crop entities not saved for uris that differ only by upper/lower case

Problem/Motivation

When two images are uploaded whose name differs only by upper/lower case, the second crop entity is not saved.

Steps to reproduce

• Install with standard profile.
• Enable media, crop and focal_point modules.
• Edit the image media type, under 'Crop configuration', choose the image field.
• Add a media item of type 'image', with a filename, eg sea.png.
• Repeat step 4 but with a filename that differs only by case, eg Sea.png

The outcome on MySQL is there is only one row in the crop & crop_field_data tables. No second crop entity is saved.

Using PostgreSQL, this error occurs upon save:

Error: Call to a member function isNew() on null in focal_point_entity_update() (line 79 of modules/contrib/focal_point/focal_point.module).

Proposed resolution

The Crop entity has a uri base field defined:

    $fields['uri'] = BaseFieldDefinition::create('uri')
      ->setLabel(t('URI'))
      ->setDescription(t('The URI of the image crop belongs to.'))
      ->setRevisionable(TRUE)
      ->setTranslatable(TRUE)
      ->setSetting('max_length', 255);

Adding setSetting('case_sensitive', TRUE) makes this match the corresponding uri property on the file entity. The error doesn't occur and both crops are saved.

Remaining tasks

• Write patch.
• Tests.
• Upgrade hook.

User interface changes

None.

API changes

None.

Data model changes

The uri column definition changes from:

varchar(255) DEFAULT NULL

to

varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL