Screen dialog cleanup - #9304

Cleanup style related items.

• Setting the style sheet is expensive so lets do it only when necessary.
• Adjust how the LineEditValidator styles lines with invalid input
  • Make it look more native based on the Qt Style in use, The style changing (not just the border) is visual noise.
    • fusion , Default used on windows / and non KDE XDG desktops
    • breeze , KDE's default style
    • macos , Used on mac os
    • windows not used by default but a stock style for Qt. Win98 like
• Remove gui/styles
• Use the Palette to color error related items when possible

Style	Before	After
Fusion
Breeze
macos
win98