Export `HookRecorder`, `RecordedHookCall` (originally `ParsedCall`),
`RunResult`, `LineMatcher`.
These types are reachable through `Pytester` and so should be public
themselves for typing and other purposes.
The name `ParsedCall` I think is too generic under the `pytest`
namespace, so rename it to `RecordedHookCall`.
The `HookRecorder`'s constructor is made private -- it should only be
constructed by `Pytester`.
`LineMatcher` and `RunResult` are exported as is - no private and no
rename, since they're being used.
All of the classes are made final as they are not designed for
subclassing.