Update the Issue Summary Table for new shared styles and improvements.

Review Request #10386 — Created Jan. 17, 2019 and submitted — Latest diff uploaded

Review Board

This updates the Issue Summary Table to derive most of its style and
structure from the common rb-review-request-field-tabular base style,
changing the structure a bit and removing much of the custom styling it
needed. The design of the table is much more simplified, reducing how
many custom CSS classes we inject into the table.

In the process, it applies a number of fixes to the table:

1) The issue text now stays aligned alongside the issue icon.
2) The issue icon is horizontally centered in relation to the avatar
icons when in mobile mode.
3) The tabs no longer wrap in a broken way on mobile mode, and the "All
Issues" is now shortened to "All".
4) The JavaScript code is much more optimized, reducing the work needed
while loading the table or applying filters.
5) The design of the table no longer assumes there's only a single
instance on the page, making it more self-contained.
6) The counter for issues being verified now properly updates.

Unit tests have also been added to test issues in verifying states.

Unit tests passed.

Tested all operations and updates extensively in mobile and desktop modes.