Allow selecting region when restoring default bands list

[Patronics]

The "reset bands" item now allows the user to select the region, thus specifying which set of defaults to restore. This makes it easier for users in region 2 or region 3 to select the appropriate bands list without manually modifying entries.

Pull Request type

Please check the type of change your PR introduces:

• [] Bugfix
• Feature
• [] Code style update (formatting, renaming)
• [] Refactoring (no functional changes, no API changes)
• [] Build-related changes
• [] Documentation content changes
• [] Other (please describe):

What is the current behavior?

The bands list currently defaults to only providing region 1 bands, which is confusing for users outside that region, where different bands are available, and the same bands have different minimum and maximum frequencies.

Issue Number: No active issues, but the confusion leads to rejected pull requests like #726

What is the new behavior?

• Now, when choosing to reset default bands, the "are you sure?" dialog allows selecting which region's band defaults to use.
• The button label is changed to "Reset bands/Select region" to improve discoverability of the new functionality.

Does this introduce a breaking change?

• [] Yes
• No

Other information

Screenshots of changed menu items:

[zarath]

It's ok. I would perhaps made it more flexible with a list of defaults, but so it is better then just having that one default.