Further simplifications regarding `get_pids*` methods

See merge request !339

Conflicts resolved:
	hive/server/condenser_api/get_state.py
	tests/tests_api

Refactoring of the SQL method `get_state`

See merge request !345

Mock data providers

See merge request !336

Mi slow get ranked post

See merge request !344

Workaround with 'id + 0'  which previously speed up the query
after some time fails and has to be removed because it slow down
get_ranked_post.

hive accounts info view optimization

See merge request !343

Redefined helper index storing author_id, created_at pair to significantly speedup hive_accounts_info_view queries.

Switch back to old gitlab ci executor

See merge request !340

Introduced `condenser_get_names_by_reblogged` SQL method

Introduced `condenser_get_follow_counts` SQL method

Introduced `condenser_get_names_by_following` SQL method

Introduced `condenser_get_names_by_followers` SQL method

hive sync fixes

See merge request !342

Improved __post_children table management in the update_all_hive_posts_children_count, to avoid an error during subsequent call.

Added missed constrain rename.

See merge request !341

Bw db upgrade support2

See merge request !338

Defined separate update_all_hive_posts_children_count to significantly improve performance of massive calculation
Disabled seq scan during execution of update_posts_rshares call to improve performance
db_upgrade measures time of every executed statement
Runtime migration is performed in separated transaction instead of single one.

Cleanup in mock classes, mock logic moved from block stream to client.py, mock vops mimic original call

Fix for issue #65

See merge request !211

remove hive_follows_block_num_idx before sync

See merge request !335

Included commit of latest develop the upgrade procedure has been prepared for.