[Rust] Primary keys for query builder views

[joshua-spacetime]

Description of Changes

Query builder views return a subset of rows from a physical table. If that table has a primary key, then so should the view. What this means concretely is that the view should expose the same api as the table, specifically as it relates to the primary key column.

With that in mind, this patch commits the following changes:

1. Annotates ViewDef with a primary_key
2. Updates the return type of query builder views in the raw module def to a special product type
3. Adds an index for the primary key on the view's backing table
4. Updates the query planner to use this index
5. Updates rust client codegen to generate on_update for such views

API and ABI breaking changes

None

Expected complexity level and risk

3

Testing

• New rust sdk integration suite exercising on_update for PK views and semijoin scenarios
• Smoketests for PK views and semijoin scenarios