* show the tags in the entry preview
* allow searching by tag
* add a sidebar listing the tags in the database
* filter entries by tag on click
* Introduce a new TagsEdit widget that provides pill aesthetics, fast removal functionality and autocompletion
* add tests for the tags feature
* introduce the "is" tag for searching. Support for weak passwords and expired added.
Rename UI elements involved with the bottom preview panel to use the
terminology "entry preview panel" instead of "details view" or "preview
panel". Change all associated variables, widgets, and classes to
reference EntryPreviewPanel. Create Config::upgrade() function and
deprecation mapping to help rename/remove previous config settings in a
clean manner.
Fixes#2327
Update state syncer (class DatabaseWidgetStateSync) to account for new
features:
- properly sync view state when switching tabs
- properly read/write view state from/to config
Update classes EntryModel and EntryView to consistenly name list/search
modes. Before, both classes defined list mode as 'group mode' and search
mode as 'entry list mode', which differed from naming in other classes
such as DatabaseWidget.
