Adds an extra item to the tab context menu (right click menu), that lets the user move a tab (or all selected tabs) into a container as requested by this Bugzilla issue.
right click a tab
press "q"
press the first letter of the new container's name
Hint: naming containers with digits helps, e.g. "1 - Personal", "2 - Work", etc.
Developer comments
I don't know how to colorize icons in context menus.
I don't consider this an issue, but switching an existing tab between containers might be considered a privacy leak, because websites can fingerprint your browser, so they still know it's you (see Am I Unique.org).
