schema: allow _cluster update after join

The function replica_check_id() is called on any change in
_cluster: insert, delete, update. It was supposed to check if the
replica ID is valid - not nil, not out of range (VCLOCK_MAX).

But it was also raising an error when the ID matched this
instance's ID unless the instance was joining. That happened even
if a _cluster tuple was updated without changing the ID at all.
For example, if one would just do
_cluster:replace(_cluster:get(box.info.id)).

Better do the check in the only place where the mutation can
happen - on deletion. Since replica ID is a primary key in
_cluster, it can't be updated there. Only inserted or deleted.

This commit is backported to 2.11, since we want to allow using
persistent names as early as we can in order to simplify the upgrade
process. We also bump the schema version in the following commit in
order to distinguish this version from overs 2.11.X, where persistent
names doesn't work.

Closes #10549

NO_DOC=bugfix and refactoring
NO_CHANGELOG=cannot happen without touching system spaces
NO_TEST=too insignificant for an own test

(cherry picked from commit cb8f4715)