Message template detail dialog is not resizable

[Flaurite]

Environment

Jmix version: 3.0

Bug Description

The msgtmp_MessageTemplate.detail opens as a fixed-size dialog that cannot be resized. The editor hosts a large content area, so a fixed, non-resizable dialog leaves too little room to work comfortably, especially for HTML templates.

I found to places where it can be faced:

1. Creating notification from BPM add-on (NotificationEdit)
2. Creating notification from Notifications add-on (CreateNotificationDialog).

Steps to reproduce

1. Open the Message Templates list from (BPM or Notifications add-ons) and click Create (or Edit an existing template).
2. In the editor, switch the template type to HTML to reveal the GrapesJS editor.
3. Try to resize the dialog.

Actual behavior

The dialog opens at a fixed size (`minWidth = 64em). The HTML/plain editing area stays cramped.

Expected behavior

The template editor dialog can be resized, and opens at a size comfortable for editing template content.