This bundles the keyName and a rune, so that we don't have to pass these around
separately everywhere. This should make it easier to swap out the rune for a
string when we upgrade to tcell v3.
I copied all files except dot files (.github and .gitignore), the _examples
folder, and go.mod/go.sum.
At some point we may want to copy the files back to the gocui repo when other
clients (e.g. lazydocker) want to use the newer versions of them.
Rebinding the universal.confirm keybinding currently doesn't make sense, because
the rebound key would also be used for editable prompts, which means you would
only be able to bind it to a ctrl key (not "y", which is desirable for some
people), and also it would allow you to enter a line feed in a branch name.
Fix this by always using enter for editable prompts.
So far, confirmations and prompts were handled by the same view, context, and
controller, with a bunch of conditional code based on whether the view is
editable. This was more or less ok so far, since it does save a little bit of
code duplication; however, now we need separate views, because we don't have
dynamic keybindings, but we want to map "confirm" to different keys in
confirmations (the "universal.confirm" user config) and prompts (hard-coded to
enter, because it doesn't make sense to customize it there).
It also allows us to get rid of the conditional code, which is a nice benefit;
and the code duplication is actually not *that* bad.
