Using consult-buffer to switch between buffers is now project aware,
meaning when current buffer is in a project, the list of buffers is
split into two groups; project buffers, and other non-project buffers.
The project buffers group is above the other buffers group, meaning it's
very easy to switch to other buffers within the same project, while
still being able to switch to non-project buffers too.
When current buffer is not part of a project, all buffers are shown
together in a single completion group.