feat: Move workspaces under organizations (#1109)

This removes split ownership for workspaces. They are now
a resource of organizations and have a designated owner,
which is a user.

This enables simple administration for commands like:
- `coder stop ben/dev`
- `coder build logs colin/arch`

or if we decide to allow administrators to access workspaces,
they could even SSH using this syntax: `coder ssh colin/dev`.

coderd/database/models.go

@@ -385,6 +385,7 @@ type Workspace struct {
 	CreatedAt         time.Time      `db:"created_at" json:"created_at"`
 	UpdatedAt         time.Time      `db:"updated_at" json:"updated_at"`
 	OwnerID           uuid.UUID      `db:"owner_id" json:"owner_id"`
+	OrganizationID    uuid.UUID      `db:"organization_id" json:"organization_id"`
 	TemplateID        uuid.UUID      `db:"template_id" json:"template_id"`
 	Deleted           bool           `db:"deleted" json:"deleted"`
 	Name              string         `db:"name" json:"name"`