Extract sql query builder

[jacek-prisma]

Extracts 2 new crates:

• sql-query-builder with sql specific query building logic
• query-builder, currently a stub but will hold abstractions for query building

I've moved some models around to decouple query building and query structure from the connector logic.

[codspeed-hq]

CodSpeed Performance Report

Merging #5123 will degrade performances by 5.51%

_{Comparing chore/extract-sql-query-builder (06f8df6) with compiler (6b19a39)}

Summary

❌ 1 regressions
✅ 10 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	compiler	chore/extract-sql-query-builder	Change
❌	build (medium)	2.5 ms	2.6 ms	-5.51%