Feature Request: improve ApplySchema multi-query performance in `direct` strategy

[shlomi-noach]

Feature Description

When ApplySchema is supplied with multiple queries, it runs a per-query loop that applies each query onto the shards. With direct strategy, we just run ExecuteFetchAsDBA.

A common scenario is when you want to bootstrap a new shard/cluster with a known schema. In that scenario, one may need to apply thousands of CREATE TABLE|VIEW statements onto the shards. Applying those one-at-a-time takes a significant toll due do network overhead.

We want to improve this performance.,

Use Case(s)

Populating new large schemas on empty shards.