Inside the generic msg command we cannot use aerc.SelectedAccount()
because the method naively assumes the current tab is an AccountView.
Use the ProvidesMessage interface instead.
Signed-off-by: Kevin Kuehler <kkuehler@brave.com>
Adds an archive command that moves the current message into the folder
specified in the account config entry.
Supports three layouts at this point:
- flat: puts all messages next to each other
- year: creates a folder per year
- month: same as above, plus folders per month
This also adds a "-p" argument to "cp" and "mv" that works like
"--parents" on mkdir(1). We use this to auto-create the directories
for the archive layout.
