Add option to select default template

[aorinngoDo]

Version running
latest (sha256:a6fd14682f3bb6bd7632c5c35ec8858db52fd56671c93336851edf81165a9361)

Describe the bug / To Reproduce

First of all, thanks for your great work.

The current behavior seems to be that the template named “default” automatically becomes the default (= automatically selected) for new downloads.

But...

• If a user deletes the original “default” template and creates a new “default” template, it appears to be selected by default in the new download screen, but in fact the settings of the added “default” template are not reflected, and the original “default” template that was deleted is used.

• Templates with other names are not available by default and must be manually selected each time they are downloaded.

Expected behavior

Here are some example solutions.

• Correctly load the newly added template named “default”.

• Make it possible to select which template to use by default.