chore: implement typed database for custom permissions (breaks existing custom roles) (#13457)

* chore: typed database custom permissions
* add migration to fix any custom roles out there

coderd/database/migrations/000214_org_custom_role_array.down.sql

@@ -0,0 +1 @@
+UPDATE custom_roles SET org_permissions = '{}';

coderd/database/migrations/000214_org_custom_role_array.up.sql

@@ -0,0 +1,4 @@
+-- Previous custom roles are now invalid, as the json changed. Since this is an
+-- experimental feature, there is no point in trying to save the perms.
+-- This does not elevate any permissions, so it is not a security issue.
+UPDATE custom_roles SET org_permissions = '[]';