Abstracting coderd into an interface added misdirection because
the interface was never intended to be fulfilled outside of a single
implementation.
This lifts the abstraction, and attaches all handlers to a root struct
named `*coderd.API`.
* feat: Add AWS instance identity authentication
This allows zero-trust authentication for all AWS instances.
Prior to this, AWS instances could be used by passing `CODER_TOKEN`
as an environment variable to the startup script. AWS explicitly
states that secrets should not be passed in startup scripts because
it's user-readable.
* Fix sha256 verbosity
* Fix HTTP client being exposed on auth
* chore: Move httpmw to /coderd directory
httpmw is specific to coderd and should be scoped under coderd
* chore: Move httpapi to /coderd directory
httpapi is specific to coderd and should be scoped under coderd
* chore: Move database to /coderd directory
database is specific to coderd and should be scoped under coderd
* chore: Update codecov & gitattributes for generated files
* chore: Update Makefile