Infer closure parameter type from call site

[abstratt]

Infer closure parameter type from call site. We should be able to invoke a closure with:

Account extent.select({ it.balance < 0 })

[abstratt]

Work is ongoing in branch issue #47

Still failing CollectionTests as of 2c0e2a31ef95536875d43fb1c661d13d816f66d8. Two challenges here:

• we compile closures after their contextual activity, so we can't infer the return type - that in itself
• some issue resolving wildcard types in the context of inference of closure parameter types

[abstratt]

Branch: https://github.com/abstratt/textuml/compare/issue-%2347