Specify YAML schemas as Python objects

[wochinge]

Description of Problem: This is a followup from #7970 . Currently all our YAML schemas which we use to validate YAML files are defined in files. This means that we have to load and parse the schema files everytime we are are validating something. This not necessary, makes the code of the function harder to read and slows down the validation.

Overview of the Solution: Pass in Python objects to validate_yaml_schema instead of file names.

Definition of Done:

• validate_yaml_schema expects a Python dictionary instead of a path to a schema
• the old usage of validate_yaml_schema is either deprecated (as it's in shared) or it was double checked with Rasa X that it is safe to remove.

[sync-by-unito]

➤ Maxime Verger commented:

💡 Heads up! We're moving issues to Jira: https://rasa-open-source.atlassian.net/browse/OSS.

From now on, this Jira board is the place where you can browse (without an account) and create issues (you'll need a free Jira account for that). This GitHub issue has already been migrated to Jira and will be closed on January 9th, 2023. Do not forget to subscribe to the corresponding Jira issue!

➡️ More information in the forum: https://forum.rasa.com/t/migration-of-rasa-oss-issues-to-jira/56569.