bug#59153: List project buffers

[Juri Linkov]

>>> This is a really helpful feature. A query though. Will that be another
>>> feature request for the users of ibuffer. May be a variable
>>> `project-list-buffers-function`.
>> Probably this could be implemented in ibuffer.el.
>> So when ibuffer is loaded, it could override the
>> keybinding 'C-x p C-b' with own function that uses
>> ibuffer filters with the current project buffers.
>
> Might as well add 'project-ibuffer' to project.el straight, similarly to
> how we have both 'project-shell' and 'project-eshell'.

Not sure where proliferating the number of keybindings for every
alternative will lead to.  I'd rather try to use more
`define-alternatives' to allow choosing alternatives between
shell/eshell, list-buffers/ibuffer, ... with the same
project keybinding.