feat: add external id to documents and templates (#1227)

## Description

Adds the external ID column to documents and templates with an option to
configure it in the API or UI.

External ID's can be used to link a document or template to an external
system and identify them via webhooks, etc.

apps/web/src/app/(dashboard)/templates/[id]/edit-template.tsx

@@ -132,6 +132,7 @@ export const EditTemplateForm = ({
         teamId: team?.id,
         data: {
           title: data.title,
+          externalId: data.externalId || null,
           globalAccessAuth: data.globalAccessAuth ?? null,
           globalActionAuth: data.globalActionAuth ?? null,
         },