scylladb

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Wojciech Mitros 3c47ab9851 mv: handle different ERMs for base and view table

When calculating the base-view mapping while the topology
is changing, we may encounter a situation where the base
table noticed the change in its effective replication map
while the view table hasn't, or vice-versa. This can happen
because the ERM update may be performed during the preemption
between taking the base ERM and view ERM, or, due to f2ff701,
the update may have just been performed partially when we are
taking the ERMs.

Until now, we assumed that the ERMs are synchronized while calling
finding the base-view endpoint mapping, so in particular, we were
using the topology from the base's ERM to check the datacenters of
all endpoints. Now that the ERMs are more likely to not be the same,
we may try to get the datacenter of a view endpoint that doesn't
exist in the base's topology, causing us to crash.

This is fixed in this patch by using the view table's topology for
endpoints coming from the view ERM. The mapping resulting from the
call might now be a temporary mapping between endpoints in different
topologies, but it still maps base and view replicas 1-to-1.

Fixes: #17786
Fixes: #18709

(cherry-picked from 519317dc58)

This commit also includes the follow-up patch that removes the
flakiness from the test that is introduced by the commit above.
The flakiness was caused by enabling the
delay_before_get_view_natural_endpoint injection on a node
and not disabling it before the node is shut down. The patch
removes the enabling of the injection on the node in the first
place.
By squashing the commits, we won't introduce a place in the
commit history where a potential bisect could mistakenly fail.

Fixes: https://github.com/scylladb/scylladb/issues/18941

(cherry-picked from 0de3a5f3ff)

Closes scylladb/scylladb#18974