feat: allow auditors to read template insights (#10860)

- Adds a template_insights pseudo-resource
- Grants auditor and template admin roles read access on template_insights
- Updates existing RBAC checks to check for read template_insights, falling back to template update permissions where necessary
- Updates TemplateLayout to show Insights tab if can read template_insights or can update template

codersdk/rbacresources.go

@@ -25,6 +25,7 @@ const (
 	ResourceReplicas                    RBACResource = "replicas"
 	ResourceDebugInfo                   RBACResource = "debug_info"
 	ResourceSystem                      RBACResource = "system"
+	ResourceTemplateInsights            RBACResource = "template_insights"
 )
 
 const (
@@ -58,6 +59,7 @@ var (
 		ResourceReplicas,
 		ResourceDebugInfo,
 		ResourceSystem,
+		ResourceTemplateInsights,
 	}
 
 	AllRBACActions = []string{