Infer sync statements for raw tables

[simolus3]

This builds on top of the new raw table options introduced in #163.

This makes the put and delete statements set on raw tables optional. If they're omitted, the sync_local step of each sync will attempt to infer them by looking at the actual columns of the table:

1. The id column will be set to the affected row id.
2. Other columns will be bound to extracted JSON values of the same name.
   • Columns marked as local-only are ignored.

Inferred statements are cached until pragma schema_version returns a new value.

For now, this does not support a dedicated _rest column that would be inferred by default. Users interested in that would have to use explicit statements instead.