Eliminate duplicate YangTextSchemaContextResolvers

ModuleInfoBackedContext creates an internal YangTextSchemaContextResolver, which is completely independent from what DOMSchemaService uses internally.

This leads to the two context being potentially misaligned and waste of both startup CPU cycles and memory.

Once we have OSGi-specific services, the DOM and Binding counterparts need to cooperate, such that the DOM part assembles the SchemaContext (and manages YangTextSchemaContextResolver) while the Binding part provides hints as to what modules are expected to crop up in bundles (as it has cross-bundle visibility into models).