Auth plugin design

Is your feature request related to a problem? Please describe.
Compiling external services, temporal server, for custom authentication is inconvenient.

Describe the solution you'd like
Authentication provides a plugin architecture where one doesn't need to compile temporal-server.

Describe alternatives you've considered

1. Golang's plugin package - https://github.com/cwjenkins/temporal/pull/1/files (quick draft that works)
2. Hashicorp plugin package - https://github.com/hashicorp/go-plugin
3. wazero/wasm as a plugin - https://github.com/knqyf263/go-plugin (this is a wrapper for reference)

Additional context
Each has their drawbacks...

1. Go's plugin package isn't very friendly which they are very open about on the packages page
2. hashi's is over RPC so its a bit of a performance hit
3. wasm is more work than desirable to get extensions going.

Curious to converse given we like temporal thus far and we are going the compile w/ custom auth route, but looking to discuss what other options may be avail.

The issue names no repository files, tests, or entry points. Start by examining how custom authentication is compiled into temporal-server, then compare the Go plugin, Hashicorp plugin, and wazero/WASM approaches described in the issue. Done would require an agreed plugin architecture and defined authentication integration behavior, which the issue does not yet specify.