Move Option stdlib optimizations into typed pipeline

[cristianoc]

Summary

• detect real invocations during type checking and annotate the typed tree
• lower those annotations directly to the existing lambda primitives instead of relying on the Parsetree PPX
• drop the Parsetree transformer, update docs/tests, and adjust runtime examples to match the new API surface

Testing

• make test (docstring generator still fails on pre-existing Stdlib_DataView snippets)

[cknitt]

As we are doing the transformation on the typed level now, shouldn't we add some type checking tests, too?

[cknitt]

Rebased after the Docstring test fixes