Scroll in all directions

# Summary
- Scroll in all 4 directions

## Scroll
Added new `scroll` action (`actions/scrolling/Scroll.java`).
This action allows scrolling in all 4 directions, just like iOS implementation.
Additionally, when scrolling sideways, an optional "scroll position" argument is supported, ranged from 0.0 to 1.0.

- Added `viewsForQuery` method to return list of all the views matching given query (`Query.java`).
  - Exposed `evaluateQueryForPath` as public to implement `viewsForQuery` (`UIQueryEvaluator.java`)

Implemented `scroll` Ruby API using new action.

## Formatting
For all touched files
- Removed trailing spaces
- Fixed blank lines (removed obsolete spaces)