"Clear customisations" template action should always trigger a confirmation dialog

[jameskoster]

Extracted from discussion in #56603.

If you perform the "Clear customisations" action in the details panel, or the document inspector, a confirmation dialog appears asking if you're sure whether to proceed.

However, in the templates data view there's no confirmation dialog.

It would be good to be consistent here, and introduce the confirmation dialog in the templates data view.

[annezazu]

Somewhat related as there are a few reset mechanism that would benefit from this: #46859

[jameskoster]

This was fixed in #60119.