bug#50344: C-x v keybinding for vc-print-branch-log

[Juri Linkov]

>> C-x v B   - vc-switch-backend
>> C-x v b c - vc-create-tag (maybe it should have an alias 'vc-create-branch'?)
>> C-x v b l - vc-print-branch-log
>> C-x v b s - vc-retrieve-tag (maybe it should have an alias 
>> 'vc-switch-branch'?)
>> C-x v s   - vc-log-search
>> C-x v r   - free, any ideas what to bind to it?
>
> vc-rename-file, perhaps?

Or use it as a prefix key to allow more keybindings, e.g.
with mnemonics "revision" to navigate the history like
in vc-annotate: 'C-x v r n' (revision-next), 'C-x v r p' (previous), ...