IBX-1580: External storage for field type settings

[adamwojs]

Question	Answer
JIRA issue	IBX-1580
Type	feature
Target Ibexa version	v4.0
BC breaks	no

Added extension point which allows o load field type settings from external source.

External storage for Field Type settings needs implement

interface FieldConstraintsStorage
{
    public function storeFieldConstraintsData(
        int $fieldDefinitionId,
        FieldTypeConstraints $fieldTypeConstraints
    );

    public function getFieldConstraintsData(
        int $fieldDefinitionId
    ): FieldTypeConstraints;

    public function deleteFieldConstraintsData(
        int $fieldDefinitionId
    ): void;
}

and be registered as a service with tag ibexa.field_type.external_constraints_storage e.g.

App\FieldType\Example\ExternalStorage:
    tags:
        - { name: ibexa.field_type.external_constraints_storage, alias: example }

Checklist:

• Provided PR description.
• Tested the solution manually.
• Provided automated test coverage.
• Checked that target branch is set correctly (main for features, the oldest supported for bugs).
• Ran PHP CS Fixer for new PHP code (use $ composer fix-cs).
• Document removeFieldDefitnion signature change
• Asked for a review (ping @ibexa/engineering).