Reorganize and polish buttons in the board header

Problem to solve

Better grouping of items in the boards header will allow the user to better scan them, and reduce the perception of visual clutter.

Proposal

• Reorder these buttons from L to R to: Label toggle, swimlanes dropdown, edit board, create list, expand board.
• Style edit board as success secondary
• Style create board as success primary
• Tweak alignment of options to make sure they are all inline-
  • For example, the swimlanes dropdown seems to have some extra button and line height, and the expand button looks a bit misaligned

Before	After