hiding Select button or VariantSwitch

[yalov]

Mods have parts with like six B9PartSwitch and more, so PAW there are huge.

B9PartSwitch has a switcher as VariantSwitch and as Select button, so it is 2 lines in the PAW.

Difficulty section settings could have an option for used PAW switcher: for example, 3-side enum: VariantSwitch, Select button, Both.

PAW of parts with large amount of B9PartSwitch will become noticeable shorter when user choose to show not both.

[alex-dev]

And with Kerbalism 4 migrating some of its configuration to B9 and removing its own Configure, I guess a feature such as this could be even more valuable to its users. I know I'd find it valuable.