feat(formlyConfigProvider): Expose field types map from formlyConfigProvider

[pcardune]

What

Adding a getTypes() method to formlyConfigProvider that returns the map of type to config.

Why

For a plugin I am writing that renders an inspector showing the current configuration for formly, I
need access to the types that have been registered with formly.

How

This change exposes the map of type name to type configuration object via a new method on formlyConfigProvider called getTypes().

For issue #663

Checklist:

• Follows the commit message conventions
• Is rebased with master
• Is only one (maybe two) commits

[codecov-io]

Current coverage is 95.87%

Merging #669 into master will increase coverage by +0.01% as of 2619e33

@@            master    #669   diff @@
======================================
  Files           16      16       
  Stmts         1161    1163     +2
  Branches         0       0       
  Methods          0       0       
======================================
+ Hit           1113    1115     +2
  Partial          0       0       
  Missed          48      48       

Review entire Coverage Diff as of 2619e33

---

Uncovered Suggestions

1. +0.34% via ...alidationMessages.js#25...28
2. +0.26% via src/test.utils.js#38...40
3. +0.26% via ...s/formlyUsability.js#18...20
4. See 7 more...

Powered by Codecov. Updated on successful CI builds.

[kentcdodds]

This looks just fine 👍

[kentcdodds]

I'd still like someone else who actually uses the library still to review and merge this though.

[kwypchlo]

LGTM if you have use case for it

[kwypchlo]

@pcardune could you provide some short docs on your feature here? http://docs.angular-formly.com/docs/formlyconfig (use suggest edit button in top right corner).

Are you still maintaining these docs @kentcdodds? I should write some docs to the stuffed I pushed too I guess...

[kentcdodds]

I am, but would love to give some other people access.