Introduce tags and context_requirements

Closes #3454615

modules/ui_patterns_field_formatters/src/Plugin/Derivative/FieldPropertiesSourceDeriverBase.php

@@ -168,13 +168,6 @@ abstract class FieldPropertiesSourceDeriverBase extends DeriverBase implements C
   public function getDerivativeDefinitionsForField(array $derivative_for_this_field, FieldStorageDefinitionInterface $field_storage_definition) {
     // Generate one plugin for each field property,
     // compatible only for the corresponding bundles.
-    $ui_patterns_component_per_item_context = new ContextDefinition('string');
-    $ui_patterns_component_per_item_context
-      ->setRequired(TRUE)
-      ->setLabel("ui_patterns_entity_field_granularity")
-      ->setDefaultValue("item")
-      // This line is fundamental, and does what we want to achieve.
-      ->addConstraint("AllowedValues", ["item"]);
     foreach ($field_storage_definition->getPropertyDefinitions() as $property_id => $property_definition) {
       // Skip entity reference
       // Description could have been more precise,
@@ -192,10 +185,9 @@ abstract class FieldPropertiesSourceDeriverBase extends DeriverBase implements C
           // @todo ,
           "description" => $description,
           "prop_types" => $this->getPropTypesDeriver($property_definition),
+          "context_requirements" => ["field_granularity:item"],
         ]
       );
-      $derivative['context_definitions'] = array_merge(
-        $derivative['context_definitions'], ["ui_patterns_entity_field_granularity" => $ui_patterns_component_per_item_context]);
       $derivative['id'] = implode(PluginBase::DERIVATIVE_SEPARATOR, [
         $derivative['id'],
         $property_id,