[Feat] New OTel-oriented filters and test predicates for Jinja

[lquerel]

This PR adds the following filters:

• attribute_registry_namespace: Converts registry.{namespace}.{other}.{components} to {namespace}.
• attribute_registry_title: Converts registry.{namespace}.{other}.{components} to {Namespace} (title case the namespace).
• attribute_registry_file: Converts registry.{namespace}.{other}.{components} to attributes-registry/{namespace}.md (kebab-case namespace).
• metric_namespace: Converts metric.{namespace}.{other}.{components} to {namespace}.
• attribute_namespace: Converts {namespace}.{attribute_id} to {namespace}.

This PR adds the following test predicates:

• stable
• experimental
• deprecated

Closing: #113