bug#70577: [PATCH] New command other-project-prefix

[Juri Linkov <juri@linkov.net>]

>> Wow, everything works now, will test more as a primary 'C-x p p' command.
>
> Thanks, let me know if you find any other problems.

I confirm that everything works nicely, thanks.  The only
problem is that after trying to use it, its order looks unnatural.
I already accustomed to this order: 1) select the project,
2) run the command.  This is handy especially with
project-switch-commands set to 'project-prefix-or-any-command'.
This order looks more logical because after selecting the
project, the user mentally switches to another project, and
then types a command with arguments in the switched project.
However, the reverse order of typing a command keys
before switching the project looks like trying
to run the command in the previous project.
Also the problem is that typing a command keys and reading
the command arguments is separated by reading a project.

Maybe many users would prefer other-project-prefix, I don't know.
But other-project-prefix can't replace project-switch-project,
only to be an alternative.