Closes https://github.com/coder/coder/issues/16775
## Changes made
- Added `OneWayWebSocket` function that establishes WebSocket
connections that don't allow client-to-server communication
- Added tests for the new function
- Updated API endpoints to make new WS-based endpoints, and mark
previous SSE-based endpoints as deprecated
- Updated existing SSE handlers to use the same core logic as the new WS
handlers
## Notes
- Frontend changes handled via #16855
* chore: add /v2 to import module path
go mod requires semantic versioning with versions greater than 1.x
This was a mechanical update by running:
```
go install github.com/marwan-at-work/mod/cmd/mod@latest
mod upgrade
```
Migrate generated files to import /v2
* Fix gen
It's possible for websocket close messages to be too long, which cause
them to silently fail without a proper close message. See error below:
```
2022-03-31 17:08:34.862 [INFO] (stdlib) <close_notjs.go:72> "2022/03/31 17:08:34 websocket: failed to marshal close frame: reason string max is 123 but got \"insert provisioner daemon:Cannot encode []database.ProvisionerType into oid 19098 - []database.ProvisionerType must implement Encoder or be converted to a string\" with length 161"
```
* 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
