Implement System.Decimal.Scale

[MichalPetryka]

Adds System.Decimal.Scale, a property that
returns the scaling factor of the decimal.

Closes#65074.

[ghost]

Note regarding the new-api-needs-documentation label:

This serves as a reminder for when your PR is modifying a ref *.cs file and adding/modifying public APIs, to please make sure the API implementation in the src *.cs file is documented with triple slash comments, so the PR reviewers can sign off that change.

[ghost]

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

[ghost]

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Issue Details

---

Adds System.Decimal.Scale, a property that
returns the scaling factor of the decimal.

Closes #65074.

Author:	MichalPetryka
Assignees:	-
Labels:	area-System.Runtime, new-api-needs-documentation, community-contribution
Milestone:	-

[deeprobin]

LGTM

[danmoseley]

Thanks for the contribution @MichalPetryka . BTW as a small nit, it is ideal to not do a force push after the review, as everything must be re-reviewed rather than just any new changes since the review. Of course in this change that is easy for us.