lib: rename internal module declaration as internal bindings
This is a follow-up to https://github.com/nodejs/node/pull/45551.
Renaming NODE_MODULE_CONTEXT_AWARE_INTERNAL to
NODE_BINDING_CONTEXT_AWARE_INTERNAL.
As these bindings are already loaded with the function internalBinding
in the JS land, the term "internal binding" can be straightforward to be adopted.