In hindsight, having a `.getMetrics()` method that just returns `this`
is somewhat weird. It's possible that it predates the existence of the
inline cast, however.
Adds a query that counts the number of type annotations of various
kinds. Intended to be used with something like MRVA to inform our
modelling decisions.
Currently the query counts the following "interesting" types in addition
to the total number of types:
- Built-in types (which are less likely to be interesting from a
modelling perspective)
- Forward declarations (i.e. annotations inside strings) which will
require a fair bit of QL machinery to interpret.
- Simple types (stuff like `foo` or `foo.bar.baz`)
- Optional types (stuff like `Optional[foo]` which from a modelling
perspective should likely be treated the same as `foo`)
- Complex types (anything that contains more complex type constructions
such as instantiations of generic types)
