This is for a point in #599 that I couldn't do on time.

New features

• Helpdesk agents can now click on the button "Make a template" on any message under helpdesk tickets. When they do that, the server will take the message content and add placeholders like {{customer_name}} in place of what matches the ticket information in the text. They can edit it as necessary, add more placeholders, then save the template for later use. They can also mark the saved reply as shared so other agents can also make use of it.
• Helpdesk agents can now use a dropdown menu in the message composer that says "Use a template" to quickly compose a message body from an existing saved reply. If the saved reply contains placeholders, these will be automatically filled in with the ticket information. If not enough information is available some placeholders can be left behind. The agent can edit the resulting message body and fill in the placeholders themselves and send the message.
• Helpdesk agents can see the saved replies of themselves and the ones from other agents in a dedicated page. They can edit or delete their own saved replies. Admins can edit or delete any saved reply. They can create a saved reply from scratch too.

Notes

• Right now the automatic placeholder placement is done using regular expression matching. This works well enough, however we can also later add an AI agent that does it.