Added patterns for bridge api tests. Tests passes on production.

- added empty pattern files for test data

Files will be filled with data in next commits.

- test definitions are now complete,
- benchmark definitions are now complete,

Now we need to add reference json data for tests (in next commits).

- updated tests bodies,
- added benchmarks for some API,

More test and benchmarks in next commit.

- added initial implementation for tests using pyresttest framework
  * note: test have no arguments added so they will not work,
    arguments will be added in next commit
- fixes in imports in "manual" tests
- program for calling enum_virtual_ops added to test timeout issues
  for given block range. Timeout issues were reported by Gandalf.

Support for comment_options_operation, percent_steem_dollars renamed to percent_hbd, changed some defaults in schemas, removed percent_steem_dollars column from hive_posts

[WIP] list_commments implmemenation: added native database_api.list_comments, raw_json data moved to proper table columns in hive_posts_cache, engine changed to support new columns. Added script to perform database upgrade.

[WIP] list_commments implmemenation: added native database_api.list_comments, raw_json data moved to proper table columns in hive_posts_cache, engine changed to support new columns. Added script to perform database upgrade.

[WIP] list_commments implmemenation: added native database_api.list_comments, raw_json data moved to proper table columns in hive_posts_cache, engine changed to support new columns. Added script to perform database upgrade.

[WIP] list_commments implmemenation: added native database_api.list_comments, raw_json data moved to proper table columns in hive_posts_cache, engine changed to support new columns. Added script to perform database upgrade.