feat: Add support for D1 JSON functions in WHERE clause

This commit introduces the ability to use Cloudflare D1's JSON
functions (e.g., json_extract, json_array_length, json_type)
within the `.where()` method of the modular query builder.

A new `json(expression, ...bindings)` helper function has been added
to allow users to specify JSON operations. The `where` method
has been updated to process these expressions and integrate them
correctly into the generated SQL query along with their parameters.

Relevant interfaces (`WhereClause`, `WhereInput`, `SelectOne`, etc.)
have been updated to support these changes. Test files have also
been updated to align with new interface requirements and to include
comprehensive unit tests for the new JSON functionality.

All tests pass after these changes.

Author: google-labs-jules[bot]