GUI-348: More CSS changes

Implemented in this pull request…
- Changed actions menu text from green to dark grey on landing pages (table and tile view)
- Fixed alignment of help expando on create new volume page
- Fixed style issues for help expando on attach volume to instance dialog on volume detail page
- Fixed create new key pair and import button alignment on create key pair page
- Center-aligned percentage indicator in snapshot progress indicator on snapshots landing page
- Fixed status colors on instances landing pages (table view)
- Bumped up tile width on landing pages
- Added shadow to sorting drop-down on landing pages