Pull in observable API from UI (#175)

* Pull in observable api...

* Progress changing stuff...

* votingBalance

* Update resul types

* Expose toBn on Moment

* Rework... WIP

* ... More type cleanups

* Linting passes

* BN helpers for UInt

* Update api-observable

* Add api-observable package.json

* Allow Struct/Tuple to create from hex string

* Future-proof Length with bitLength (u64/u128 compant encoding PR out)

* Make Compact number encoding shareable

* Split Api into functional sections

* Cleanup types

* Additional per-use comments

* Remove params/primitives from README

* api-format  -> api-codec

* Whitespace.

tsconfig.json

@@ -6,6 +6,7 @@
     "paths":
     {
       "@polkadot/api-codec/*": ["packages/api-codec/src/*"],
+      "@polkadot/api-observable/*": ["packages/api-observable/src/*"],
       "@polkadot/api-provider/*": ["packages/api-provider/src/*"],
       "@polkadot/api-rx/*": ["packages/api-rx/src/*"],
       "@polkadot/api/*": ["packages/api/src/*"],