Make read-only and frozen form views less form-like and other fixes (CFM-491)

[arlen]

This PR solves a number of problems from CFM-491 including:

• Make read-only input fields and frozen forms look like plain text (i.e. remove border and padding)
• Output sponsor / manager in read-only or frozen forms as simple names and links
• Make “configure” and “unfreeze” links render properly (and make them more button-like)
• Make sure modal cancel “X” button sits in the upper right corner of the modal
• Icon sizes should remain consistent in Menu Panels when left-sidebar is contracted and expanded

[arlen]

This PR now also includes the fix for CFM-469 allowing the people picker to be "unset" when a user clears the field. This was added to this ticket because the other commits already touch the autocomplete component in meaningful ways (and this will avoid conflicts).

[arlen]

This PR was also rebased against the latest develop.