docs: Add a field types catalog for model YAML types

[abdulawalarif]

Summary

• Adds a Field types reference that maps every model YAML type to Dart, Postgres, SQLite, and JSON, including defaults, indexes, query operators, and storage caveats.
• Trims the models page type list so that page stays a format guide, and links the catalog from Working with models, Tables, Model reference, Dynamic fields, Vector and geography, and Client-side database.
• Documents previously missing mappings: int as Postgres bigint, BigInt as text, Duration sharing bigint with int, ByteData protocol JSON, record {p,n} shape, SQLite encodings, and random_v7 on UUID ids.

Closesserverpod/serverpod#4517.

Test plan

• Open Field types from the Models sidebar (between Working with models and Inheritance).
• Scan the overview tables, then jump to a few type sections (int, DateTime, UuidValue, collections/records, JSON vs JSONB).
• Follow inbound links from Working with models, Tables, Model reference, Dynamic fields, Vector and geography, and Client-side database.
• Confirm #supported-types on Working with models still works, and that inheritance / dynamic / custom serialization / shared packages URLs are unchanged after the file renumber.