DlgPrefController layout fixes

[ronso0]

No description provided.

[ronso0]

Note that keepng the device info minimal was the only way to avoid random device/mapping info layout changes when going through the mapping list. I understand the horizontal 50/50 split for these groupboxes would be nice but I didn't find a way to set such a ratio and at the same time a) keep the layout static and b) give both groupboxes the space they need.
(actually 40/60 device strings don't seem to be long, but mapping descriptions can use more space)

Hope you agree with the removal of "handling".

[coveralls]

Pull Request Test Coverage Report for Build 13000033798

Details

• 0 of 2 (0.0%) changed or added relevant lines in 1 file are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage remained the same at 31.801%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/controllers/dlgprefcontroller.cpp	0	2	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/controllers/dlgprefcontroller.cpp	2	0.0%

Totals
Change from base Build 12553291147:	0.0%
Covered Lines:	33336
Relevant Lines:	104828

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💛 - Coveralls