fix(SnapshotOperations): filter out SI/MV tables
fix(SnapshotOperations): filter out SI/MV tables

we need to filter SI/MV since we can't take
snapshots of those kind of tables:

```
nodetool: Scylla API server HTTP POST to URL '/storage_service/snapshots' failed:
std::invalid_argument (Do not take a snapshot of a materialized view or a
secondary index by itself. Run snapshot on the base table instead.)
```

since this nemesis is randomlly select which snapshot
to take (and not all of our cases has SI/MV), we rarly seen this
happening

Fixes: #4775

scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests