Remove \Drupal\jsonapi\RequestCacheabilityDependency, use \Drupal\jsonapi\JsonApiSpec::getReservedQueryParameters() instead

This:

1. marks JsonApiSpec @internal
2. adds two official query parameters that we missed in #2829328: Clean up Drupal\jsonapi\Access\CustomParameterNames and make it follow the spec more closely: fields and include.
3. removes RequestCacheabilityDependency::getQueryParamCacheContextList(), because that can now be read from JsonApiSpec::getReservedQueryParameters()

Note that #2 passes tests, so RequestCacheabilityDependencyTest passes. But that test really is pretty pointless. So, removing it.

In fact, we can remove RequestCacheabilityDependency altogether. It was only being used in one place: \Drupal\jsonapi\Normalizer\Value\JsonApiDocumentTopLevelNormalizerValue::__construct().

I'm not convinced that's entirely the correct place, but that's a problem for later. What matters most right now, is that we have less duplication, and also one less class that is rather strange-looking.

#2829328: Clean up Drupal\jsonapi\Access\CustomParameterNames and make it follow the spec more closely is in, we can continue here.

#4 causes \Drupal\Core\Cache\RefinableCacheableDependencyTrait::addCacheContexts() to be called, which calls Cache::mergeContexts(), which uses the cache contexts manager. That's what's causing this to fail.

+++ b/src/Normalizer/Value/JsonApiDocumentTopLevelNormalizerValue.php
@@ -74,7 +74,10 @@ class JsonApiDocumentTopLevelNormalizerValue implements ValueExtractorInterface,
+    $reserved_jsonapi_query_parameters = JsonApiSpec::getReservedQueryParameters();
+    foreach ($reserved_jsonapi_query_parameters as $query_parameter_name) {
+      $this->addCacheContexts([sprintf('url.query_args:%s', $query_parameter_name)]);
+    }

#7: let's convert this to an array_map() then :)

Done.

LOL of course. Thanks.

Wim--