fix email template

- fix verification types
- add design to cassandra db provider for email_template
- fix default email verification types to include update_email

server/test/update_email_template_test.go

@@ -32,6 +32,7 @@ func updateEmailTemplateTest(t *testing.T, s TestSetup) {
 			ID:       emailTemplate.ID,
 			Template: refs.NewStringRef("Updated test template"),
 			Subject:  refs.NewStringRef("Updated subject"),
+			Design:   refs.NewStringRef("Updated design"),
 		})
 
 		assert.NoError(t, err)
@@ -44,5 +45,6 @@ func updateEmailTemplateTest(t *testing.T, s TestSetup) {
 		assert.Equal(t, emailTemplate.ID, updatedEmailTemplate.ID)
 		assert.Equal(t, updatedEmailTemplate.Template, "Updated test template")
 		assert.Equal(t, updatedEmailTemplate.Subject, "Updated subject")
+		assert.Equal(t, updatedEmailTemplate.Design, "Updated design")
 	})
 }