Add TypeScript declarations

[vsund]

I added TypeScript declarations to my fork some time ago. I talked with @jackzampolin about this and he said that I should add a PR to create a platform to discuss. Whether we merge this or not, I'd like to kick off a discussion about:

1. Is this PR the best way to enable TypeScript developers to use blockstack.js?
2. How do we assure that the types are up to date with the exposed methods?
3. How do we assure that the types are correct / complete?
4. A more general one: While collecting these types, I had some hard times on understanding methods and their return types (can give examples if needed). The return types of some methods are quite confusing and personally as a developer I would expect them to be a bit more descriptive and consistent (can give examples if needed). This might be totally out of scope for this PR, but though I'd like to raise this issue somewhere: How should we deal with this code? Should we refactor (rewrite?) these?

---

Todo

This PR isn't fully complete yet. Things still to do:

• Full coverage of exported methods (see ./src/profiles/index.d.ts)
• Add method documentation for hints in code completion
• Add TypeScript tests (see tests/typescriptTests/index.ts)
• Resolve some unclear types
  • in ./src/index.ts
  • in ./src/auth/index.d.ts
  • in ./src/auth/index.d.ts
  • in ./src/profiles/index.d.ts
  • in ./src/profiles/index.d.ts
  • There are still some any types in the declaration files; need to revisit them to check if there are more precise return types

cc @larrysalibra @jackzampolin

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[jackzampolin]

Thanks for the PR @vsund! We will discuss this at the next engineering meeting.

[vsund]

Just noticed that I originally branched it of master but then started merging in constantly develop to keep up with newer code 🙈

This shouldn't change anything since we use git flow and master is basically a snapshotted version of develop, but people might have committed into master manually (since my branch off). So I should be simply able to change the branch to raise against to develop (these potential master commits should come in when we merge develop into master next time).

We definitely should double-check this PR.

[vsund]

Just for reference, I'm probably going to abandon this in favor of my blockstack.ts fork.
For progress on the port see ntzwrk/blockstack.ts#3.

Going to close this, can reopen if needed.