feat: email sending and invites backend code

apps/api/src/services/email/utils.py

@@ -0,0 +1,19 @@
+import resend
+from config.config import get_learnhouse_config
+
+def send_email(to: str, subject: str, body: str):
+    lh_config = get_learnhouse_config()
+    params = {
+        "from": f"LearnHouse <"
+        + lh_config.mailing_config.system_email_address
+        + ">",
+        "to": [to],
+        "subject": subject,
+        "html": body,
+    }
+
+    
+    resend.api_key = lh_config.mailing_config.resend_api_key
+    email = resend.Emails.send(params)
+
+    return email