Create builder for 'MetaProperty' implementations

[nipafx]

The current implementations of MetaProperty are package visible and can hence not be used outside the project. To resolve this issue one or several public builders to instantiate those implementations should be implemented.

[jodastephen]

Fundamentally, the only query callers want to make is MetaBean.of(Class) The MetaProperty implementations can be package scoped because they never need to be seen, only via the interface.

What might turn out to be necessary is a way to select how MetaBean.of(Class) works, but lets see how far we can get with a single fixed implementation of the introspector.