feat: add textWidth option to dialog.showMessageBox()

[miniak]

Description of Change

This allows working around the overly narrow NSAlert dialogs on macOS Big Sur. Default:

textWidth = 420:

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• relevant documentation is changed or added
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Added textWidth option to dialog.showMessageBox() / dialog.showMessageBoxSync().

[codebytere]

I agree this is a problem worth addressing, but my mild concern here is that this solution is a bit narrow and might prevent us from addressing other similar issues in a more robust way in the future.

For example - with this users can specify a custom width, but would they ever experience issues with height? Would it perhaps make more sense to specify x, y, width, height as a gfx::Rect here? If that's a potential i'd definitely want to avoid adding more one-off properties than necessary 🤔

[miniak]

I agree this is a problem worth addressing, but my mild concern here is that this solution is a bit narrow and might prevent us from addressing other similar issues in a more robust way in the future.

For example - with this users can specify a custom width, but would they ever experience issues with height? Would it perhaps make more sense to specify x, y, width, height as a gfx::Rect here?

@codebytere It's only possible to specify width. I am using a dummy https://developer.apple.com/documentation/appkit/nsalert/1530575-accessoryview?language=objc, which has specified width and zero height. There does not seem to be any other good way to make the dialog wider.

[zcbenz]

The API looks good to me.

[release-clerk]

Release Notes Persisted

Added textWidth option to dialog.showMessageBox() / dialog.showMessageBoxSync().

[trop]

I have automatically backported this PR to "15-x-y", please check out #31088

[trop]

I have automatically backported this PR to "16-x-y", please check out #31089