[Color Picker] Don't wait for ColorPicker.exe to close

[ivan100sic]

Summary of the Pull Request

Unlike PowerLauncher, we can safely immediately terminate ColorPicker.exe when the module is disabled/PT quits.

PR Checklist

• Applies to ColorPicker and PT Run take 10 seconds to exit #5860
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Validation Steps Performed

Ran PT, enabled/disabled Color Picker, terminated PT and checked that CP quits, also all of this when running as admin.