feat!: drop reading other 'user' permission (#8650)

* feat: drop reading other 'user' permission

Members of the platform can no longer read or list other users.
Resources that have "created_by" or "initiated_by" still retain
user context, but only include username and avatar url.

Attempting to read a user found via those means will result in
a 404.

* Hide /users page for regular users
* make groups a privledged endpoint
* Permissions page for template perms
* Admin for a given template enables an endpoint for listing users/groups.

enterprise/coderd/coderd.go

@@ -202,6 +202,7 @@ func New(ctx context.Context, options *Options) (_ *API, err error) {
 				apiKeyMiddleware,
 				httpmw.ExtractTemplateParam(api.Database),
 			)
+			r.Get("/available", api.templateAvailablePermissions)
 			r.Get("/", api.templateACL)
 			r.Patch("/", api.patchTemplateACL)
 		})