Proto commits in temporalio/api-go

These 3 commits are when the Protocol Buffers files have changed:

Commit:ef53164
Author:Stephan Behnke
Committer:Stephan Behnke

Add api_next draft Go module generation

Commit:306db99
Author:Spencer Judge
Committer:GitHub

Improve proxy codegen by using proto descriptors (#210)

The documentation is generated from this commit.

Commit:3be2272
Author:Tim Deeb-Swihart
Committer:GitHub

Port protojson coding stack to support shorthand HTTP payloads (#134) Our old shorthand payload support was built upon gogo/protobuf's json coding stack, which won't work with google/protobuf. This commit ports and adapts the official protojson coding code (and some of its internals) to allow for both: 1. shorthand JSON payloads for our HTTP API 2. efficient support for both new and old-style JSON enums This replaces the recursive fixup code I included in my previous proto work.