[TIMOB-10577] iOS: Kroll: Introspection is too introspective

Ever since 0.9, we expose properties based on key value coding and checking for method selectors. The problem is that this inadvertently expose items that:

Internal proxy properties not designed to work with JS

NSObject properties and methods not designed for JS

For example, TiWindowProxy has an internal method _window pointing to the App's UIWindow. Or even more comically, the -[retain] and -[autorelease] meet the signature of a property. JS can refer to these false properties and crash the app. This is bad. This was part of the design, dating back to 0.9. Steps:

Come up with new protocol that is not KVC-discoverable

Implement secondary protocol

Transition to secondary protocol

Phase out older KVC-based ones