Lossy compression ratio tag is overwritten after compression

[BobSter3000]

Describe the bug
Lossy Compression Ratio Tag, (0028,2112) is a multi-value tag if successive lossy compression steps have been applied. Currently fo-dicom overwrites the tag instead of adding another value to the tag.

To Reproduce
Perform lossy compression on an image that already has the lossy compression ratio tag with a value set and review the lossy compression tag. Note only one value is present.

Expected behavior
The original values will have an additional value applied.

Screenshots or test DICOM files
If applicable, add screenshots or test DICOM files to help explain your problem.

Environment
Fellow Oak DICOM version: 5.0.3
OS: Windows 10 x64
Platform: .NET 6.0

I have a potential fix and will submit a PR.