Ability to see IMAP keywords in message view

[philipwhiuk]

Expected behavior

Be able to see IMAP keywords

Actual behavior

Only specific keywords are handled (e.g. Flagged). Most keywords are only visible in headers.

Developer notes

See #558 for starting work and design discussion. Further design discussion should be had to look at what features are required and how various clients handle these tags.

[ccoenen]

The list of tickets is growing:

• https://code.google.com/archive/p/k9mail/issues/2532 (2010! Seven years!)
• https://code.google.com/archive/p/k9mail/issues/4101 (lots of discussion)
• IMAP Keywords support. #146 (PR)
• IMAP Keywords (rebased) #558 (PR)
• Add support for IMAP labels #769 (discussion)

And in one of these I found two bountys:

• https://www.bountysource.com/issues/26376747-add-support-for-imap-labels
• https://www.bountysource.com/issues/817243-feature-suggestion-use-imap-keywords-user-defined-flags-tags-labels

[cketti]

See #769

[daniele-athome]

And k9mail/k9mail.github.io#57 just appeared :-)