Is your feature request related to a problem? Please describe.
Since the evolog can have branches and doesn't have to be linear, sometimes running jj evolog -r xyz isn't sufficient to see all commits with change ID xyz. For instance, sometimes I rewrite a commit xyz a few times, then I decide I don't like the changes I made, so I revert back to an old version from the evolog. But then later I decide I actually wanted to explore those changes further. However, since the evolog only shows predecessors, it's now difficult to find those changes.

Describe the solution you'd like
We could implement a revset like xyz/*, which returns all commits with change ID xyz (including hidden commits). This is a natural extension of the xyz/<N> syntax we implemented recently.

For instance, jj evolog -r 'xyz/*' might show this graph:

* xyz/0 - E (hidden)
|
* xyz/1 - D (hidden)
|
@ xyz - C
|
| * xyz/3 - B (hidden)
|/
*  xyz/4 - A (hidden)
|
~

Whereas a simple jj evolog -r xyz only would've shown:

@ xyz - C
|
* xyz/4 - A (hidden)
|
~

Describe alternatives you've considered
This could also be done with a new argument to the change_id() function, such as change_id(xyz, include_hidden=true).