Improvements

• #5533: Support for PostgreSQL schemas in sql-tracker-store. The SQLTrackerStore accesses schemas defined by the POSTGRESQL_SCHEMA environment variable if connected to a PostgreSQL database.

  The schema is added to the connection string option's -csearch_path key, e.g. -options=-csearch_path=<SCHEMA_NAME> (see https://www.postgresql.org/docs/11/contrib-dblink-connect.html for more details). As before, if no POSTGRESQL_SCHEMA is defined, Rasa uses the database's default schema (public).

  The schema has to exist in the database before connecting, i.e. it needs to have been created with

  CREATE SCHEMA schema_name;
  

Bugfixes

• #5547: Fixed ambiguous logging in DIETClassifier by adding the name of the calling class to the log message.