Missing link in text/plain sections of offline message alert email

Description:

Offline message email alerts sent with either "Send only plain text emails" enabled or when rendered in a plain/text email client are missing a link to for the "GO TO MESSAGE" button.

Steps to reproduce:

1. Receive an offline message alert
2. View email as plain text

Expected behavior:

A link to the missed message is included in the email text body

Actual behavior:

----_NmP-bfb1301f864d2641-Part_1
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit

admin sent you a message GO TO MESSAGE
----_NmP-bfb1301f864d2641-Part_1
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: quoted-printable

Server Setup Information:

• Version of Rocket.Chat Server: 7.1.0
• License Type: Enterprise
• Number of Users: 3k
• Operating System: Debian
• Deployment Method: Binary
• Number of Running Instances: 1
• DB Replicaset Oplog: x
• NodeJS Version: v20.5.1
• MongoDB Version: 6.0.19

Client Setup Information

• Desktop App or Browser Version: n/a
• Operating System: n/a

The report names no source file, test, or entry point. Start by reproducing an offline message alert with plain-text email output, then locate the code that assembles that alert. Done means the plain-text body includes a usable link to the missed message while the existing HTML behavior remains intact.