Magn-9966 Crash when closing a Custom Node with a Group when in Sweden or France

[sm6srw]

Purpose

Make sure that all convert methods are using the correct culture when converting to double. There are currently three different convert methods where we don't do that. These are:

ZoomToVisibilityConverter
MenuItemCheckConverter
GroupFontSizeToEditorEnabledConverter

These convert methods are in 99% of all cases passed a double at convert time and the current culture doesn't matter but there are a few cases where a string is passed in instead and that is when we will get invalid format exceptions in regions of the world that use "," instead of "." as the decimal point.

Declarations

Check these if you believe they are true

• The code base is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• [] User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.

Reviewers

@ramramps

FYIs

@mjkkirschner @QilongTang

[ramramps]

LGTM