Resize quality improvements

[JimBobSquarePants]

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Description

Squeezed a bit of improved quality out of the Resize Processor. We're now producing the best quality that System.Drawing will allow. Fix #792

In addition I replaced the inline dimension calculation code with the ResizeHelper used in the V3 branch and fixed a long standing issue parsing center coordinates in the web project.

Light on tests but the code is heavily tested in the v3 branch and it's copy/paste so not going to bother adding as the infrastructure isn't present.

[ronaldbarendse]

I've added some fixes and ensured ResizeLayer is backwards compatible again (no binary breaking change and no swapping of X/Y coordinates), but the ResizeHelper still uses the validated and unambiguous PointF? (currently only as internal property).

[ronaldbarendse]

Backwards compatibility is fixed nicely in the latest commit 👍

We only have to check the implementation of the QueryParamParser.Instance.ParseValue<PointF>(...), as invalid center values will now default to 0,0 (initial values of the empty struct).

[ronaldbarendse]

@JimBobSquarePants This is ready to merge! If you can do a last check, this can be released right away (I've already made a draft release containing all changes and versions to bump/release).