fix(core): Make email for UM case insensitive (#3078)

* 🚧 lowercasing email

* ✅ add tests for case insensitive email

* 🐘 add migration to lowercase email

* 🚚 rename migration

* 🐛 fix package.lock

* 🐛 fix double import

* 📋 add todo

packages/cli/src/UserManagement/email/UserManagementMailer.ts

@@ -12,6 +12,7 @@ import {
 } from './Interfaces';
 import { NodeMailer } from './NodeMailer';
 
+// TODO: make function fully async (remove sync functions)
 async function getTemplate(configKeyName: string, defaultFilename: string) {
 	const templateOverride = (await GenericHelpers.getConfigValue(
 		`userManagement.emails.templates.${configKeyName}`,