fix: resolve mypyc compilation bugs, exception handling, filter providers, and vector distance SQL generation

[cofin]

Summary

• Fixed mypyc compilation bugs: Refactored async iterators to avoid fragile mypyc coroutine state machines. Removed unstable __del__ methods causing C-level race conditions during GC.
• Fixed exception handling: Wrapped execute methods in exception handler so mapped SQLSpec exceptions propagate correctly (instead of raw driver exceptions leaking through).
• Fixed IN/NotIn filter providers: create_filter_dependencies with in_fields now correctly produces InCollectionFilter instances. Fixed FieldNameType resolution for string field definitions.
• Fixed vector distance SQL generation: Invalidate sqlglot's _DISPATCH_CACHE after registering custom TRANSFORMS, so dialect-specific vector distance operators (pgvector <->, MySQL DISTANCE(), Oracle VECTOR_DISTANCE(), etc.) are actually used instead of generic OPERATOR() syntax.
• Added set_migration_config(): Migration configuration can now be attached after initial config creation via property setter or explicit method.
• Moved to TypedDicts for config: Connection configs now use TypedDicts for better type safety and IDE support.
• Psycopg type safety: Added shims for type aliases in _typing.py to resolve pyright errors.
• Path resolution fix: Corrected SQLFileLoader to handle alias-relative paths and identical path/base_path cases.
• Updated dependencies: Corrected import paths in asyncmy and postgres dialects.

Closes

• Closes Bug: some circumstances allow raw driver exceptions to leak through #362 — raw driver exceptions leaking through compiled sqlspec
• Closes create_filter_dependencies: IN filters never applied to queries #405 — create_filter_dependencies IN filters never applied to queries
• Closes Enhancement: add a migration config to a driver config #352 — add migration config to a driver config post-construction
• Closes Enhancement: could connection_config be typed better ? #351 — connection_config typed better with TypedDicts