Add context popup for containers when creating a tab (particularly via keyboard shortcut)

[clairity]

this is somewhat related to #245, #311, and #518. i'd love cmd-t (and equivalents on other OSes) to provide a context menu to choose the container type to open. so

1. cmd-t to signal the desire for a new tab
2. display context menu of containers available, numbered so i can choose the type with a number

    0  Default
    1  Personal
    2  Work
    3  Financial

3. type number of container desired for the tab (e.g., type in 1 for a Personal container)

this might need a configuration setting for how cmd-t behaves since some people may not want the extra context menu, or this flow can be triggered by a more complicated keyboard shortcut (like ctrl-cmd-t on mac).

this context menu also could be used when cmd-/ctrl-clicking links or converting tabs from one type of container to another (selectable via keyboard number, click or touch, and possibly auto-hiding after a couple seconds or via esc).

┆Issue is synchronized with this Jira Task

[groovecoder]

As of this week, there's a keyboard shortcut to open the pop-up, and to tab down to a container. So the steps are:

1. Ctrl+y (or Cmd+y on Mac)
2. Tab down to the container you want
3. to open a tab in that container

[jonathanKingston]

We have not announced this feature yet as if you have a text field focussed this doesn't work. This includes the URL bar too.

I'm looking into ways we can expose this more. Adding numbers for keyboard navigation is certainly something we can do for #512.

[jonathanKingston]

I have also raised #546 to move this to Ctrl+Comma as it has URL bar issues.

[clairity]

@groovecoder @jonathanKingston thanks for the update!

the only disadvantage of ctrl-y or ctrl-, is that it's another key combo to remember vs. overriding the already existing ctrl-t shortcut (from the user's perspective, the browswer just automagically realizes you are using containers and asks you to choose which one you would like).

and tabbing to select in a dropdown list is not as intuitive (to me) as either (1) using arrow keys or (2) choosing numbers, but if that's the implementation, then i can live with it.

in any case, focusing on the url bar afterwards is definitely key (pun intended) to an efficient keyboard-based workflow. 😊

[jonathanKingston]

@clairity focusing the URL bar will come back (this is available in Nightly and I think Beta), we are not sure about the keyboard shortcut alternative as of yet.

[audreytoskin]

More than numbers or Tab, I would expected to select the container type with the arrow keys. You can use the arrow keys after the first Tab, but not till after that.

[dlee]

Currently, I can only use ctrl-. (not Cmd-.) on a Mac to show the popup.

It would be nice if it was Cmd-. instead. Also, arrow keys and ctrl-n/ctrl-p should be used to navigate between the choices (currently arrow keys work if you tab in first, but ctrl-n/ctrl-p does not work at all).