The maximal unix socket file length is 108 symbols on Linux, so
we should decrease file name to fit in this size.

ER_TUPLE_FOUND message shows only space and index, let's also show old
tuple and new tuple.

This commit changes error message in code and in tests. Test sql/checks
and sql-tap/aler remain the same due to problems in showing their old
and new tuples in error message.

Closes #5567

In previous version of patch we compared memtx state with
MEMTX_FINAL_RECOVERY to check that memtx recovery completed.
This is not quite true, memtx_state == MEMTX_FINAL_RECOVERY
means that the recovery from snapshot is finished, but recovery
from wals not. We need to compare memtx_state with MEMTX_OK
to check that recovery totally finished.
In previous test version on_replace trigger (created on
_user space) is never called. It's because is_recovery_finished()
always returns false: on_schema_init is invoked BEFORE
user's data recovery process (so trigger is not created at all
at this moment).
In new test version you can see correct user case:
we create on_replace trigger on _index system space,
which replaces/inserts/updates tuples in temp and loc spaces.
So each time user creates new space and index for it,
trigger replaces/inserts/updates tuples in temp and loc spaces.
Because trigger replaces/inserts/updates tuple with same
primary key, we get error when insert trigger called.

Follow-up #5304

There was a problem whith on_schema_init trigger.
This trigger gives a way to create on_replace trigger
that will modify temporary or is_local spaces during recovery
from snapshot, but on that stage of recovery process
all space indexes are in special build mode when no check
for uniqueness are made. I added a new function
'is_recovery_finished' in box.ctl, which gives
user ability to check that we are in snapshot recovery stage
and can't insert/replace/update/upsert something. Also i added a
check for corresponding operations, now they are failed
if user tries to do them during snapshot recovery.

@TarantoolBot document
Title: Add 'is_recovery_finished' function
Add 'is_recovery_finished' function in box.ctl
to add user ability to check that we are
in snapshot recovery stage and can't
insert/replace/update/upsert something

Closes #5304