[Task]: Use cached sqlite statements

[Mirko-von-Leipzig]

Node's components affected by this task

• RPC
• Block producer
• Store
• Protobuf messages
• Testing

What should be done?

We currently use prepare to create sqlite statements, however we should use prepare_cached as parsing a statement is a non-trivial cost.

How should it be done?

Analyze the sql statements in crates/store/src/db/sql.rs and change every common one to use prepare_cached.

Exceptions should be made for statements which should be rare. Alternatively (and maybe additionally), we should change the cache size which currently defaults to 16 to something large enough to handle all statements..

When is this task done?

All relevant prepare are changed to prepare_cached and the default cache size has been changed (or at least address why it should not be changed).

Additional context

#419 (comment)