feat: Remove magical parameters from being injected (#371)

* ci: Update DataDog GitHub branch to fallback to GITHUB_REF

This was detecting branches, but not our "main" branch before.
Hopefully this fixes it!

* Add basic Terraform Provider

* Rename post files to upload

* Add tests for resources

* Skip instance identity test

* Add tests for ensuring agent get's passed through properly

* Fix linting errors

* Add echo path

* Fix agent authentication

* fix: Convert all jobs to use a common resource and agent type

This enables a consistent API for project import and provisioned resources.

* Add "coder_workspace" data source

* feat: Remove magical parameters from being injected

This is a much cleaner abstraction. Explicitly declaring the user
parameters for each provisioner makes for significantly simpler
testing.

coderd/parameter/compute.go

@@ -11,11 +11,6 @@ import (
 	"github.com/coder/coder/database"
 )
 
-const (
-	CoderUsername            = "coder_username"
-	CoderWorkspaceTransition = "coder_workspace_transition"
-)
-
 // ComputeScope targets identifiers to pull parameters from.
 type ComputeScope struct {
 	ProjectImportJobID uuid.UUID