3.x: Add comprehensive tablets tests for statement execution

[dkropachev]

Add tests that ensures that tablet information is provided by server and it reaches the metadata in every case.
Sessions:

1. Session built with keyspace
2. Session with executed USE ks
3. Session with no keyspace assigned

Query types by data:

1. Concrete (prepared and not): SELECT * FROM ks.t WHERE pk = 1 AND ck = 1
2. Regular prepared: SELECT * FROM ks.t WHERE pk = ? AND ck = ?
3. Concrete prepared: SELECT * FROM ks.t WHERE pk = 1 AND ck = ?

Query types by op: SELECT, UPDATE, INSERT, DELETE, LWT_UPDATE_IF, LWT_UPDATE_IF_EXISTS, LWT_INSERT_IF_EXISTS, LWT_MANUAL_SELECT, LWT_MANUAL_UPDATE, LWT_MANUAL_INSERT, LWT_MANUAL_DELETE

LWT_MANUAL - when you force query to be LWT by enforcing consistency level to SERIAL

Query types by ks presence:

1. With KS: SELECT * FROM ks.t WHERE ...
2. Without KS: SELECT * FROM t WHERE ...

[dkropachev]

Implemented here: #510