chore: improve some typings

[SamMousa]

No description provided.

[SamMousa]

Can this be reviewed? Tests fail because they are brittle not because there's anything wrong with the code.

[tsv2013]

Please check error logs. Linter checks are not passed:

D:\a\1\s\survey-creator\packages\survey-creator-core\src\property-grid\index.ts
673:29 error Expected a comma @typescript-eslint/member-delimiter-style
674:24 error Expected a comma @typescript-eslint/member-delimiter-style

D:\a\1\s\survey-creator\packages\survey-creator-core\src\property-grid\values.ts
22:28 error Expected a comma @typescript-eslint/member-delimiter-style

✖ 3 problems (3 errors, 0 warnings)
3 errors and 0 warnings potentially fixable with the --fix option.

[SamMousa]

Thanks for the feedback! I did actually (try to) interpret the logs, but honestly it's very unclear with the use of azure pipelines for anyone not familiar with them.

I've created #5434 to aid future contributors including myself.