Move namespaces to more private names.

[kitsonk]

Fixes #2888

This is effectively a temporary fix to #2888 until we restored the lib generation and address it longer term. All internal namespaces in the lib file have been moved to something that starts with __ to indicate their internal nature, so they are unlikely to "squat" on runtime code/variables.

[ry]

LGTM

Is it possible to reorganize lib.deno_runtime.d.ts such that these names are not used at all? EG: if we remove the namespaces - or move everything into a single _deno_internal namespace? This PR is certainly an improvement, but "__blob" will still be exposed to users. It would be good to eliminate or reduce the number of private symbols exported. That can help to serve as a target for future automation output.

[kitsonk]

Is it possible to reorganize lib.deno_runtime.d.ts such that these names are not used at all? EG: if we remove the namespaces - or move everything into a single _deno_internal namespace? This PR is certainly an improvement, but "__blob" will still be exposed to users. It would be good to eliminate or reduce the number of private symbols exported. That can help to serve as a target for future automation output.

I am going to work on another PR that integrates directly into the compiler services and will try to do what is proposed in the conversations with TypeScript team about trying to flatten all the definitions. This should be a situation where there is only the global namespace and the Deno namespace.