feat: async http client (#22)

* Try async

* Async http client

* mark sendable

* Shutdown client

* Use sync shutdown

* Refactor body

* Fix text body

* Fix concurrency issues

* Update readme with isolated

Fix Vapor handler

Swift v6

Cleanup server logs

Simplify with cjs file extension

Support arm64 Lambdas (#17)

* Build on native arch

* Support custom architecture

* Output architecture

* Strip

* Force build lhr

* Try args

* Try pre

* Pass debug

* Fix region name

* Another

* Another

* Cleanup

* Beef up trailing slash regex

* Remove build region

Fix express handler setup conformance

Fix vercel encoding

Cleanup

Cleanup handlers and api signatures