add macro abstractions for prepared statements

all prepared statements currently require a bunch of ceremony around building and using them. a macro abstraciton would make this much nicer.

cheers

Start by locating how prepared statements are currently built and used in the repository, then review the surrounding SQLite wrapper API. Define the intended macro abstraction and its completion criteria before implementation, since the issue does not specify the interface, affected files, or tests.

Written by the indexing model from the issue text.