[ABW]: implementation of get_discussions_by_created now reuses bridge api equivalent

hive/db/schema.py

...db/sql_scripts/bridge_get_ranked_post_for_communities.sql

hive/db/sql_scripts/condenser_get_discussions_by_created.sql

hive/server/bridge_api/methods.py

hive/server/condenser_api/methods.py

tests/tests_api