Settings_Engine: Ensure SaveSettings also updates settings in memory

[FraserGreenroyd]

Fixes #3295

[FraserGreenroyd]

@BHoMBot check compliance
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[bhombot-ci]

@FraserGreenroyd to confirm, the following actions are now queued:

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[bhombot-ci]

The check code-compliance has already been run previously and recorded as a successful check. This check has not been run again at this time.

[bhombot-ci]

The check documentation-compliance has already been run previously and recorded as a successful check. This check has not been run again at this time.

[Tom-Kingstone]

Addition makes sense as a user otherwise would have to reset whenever changing settings.

[FraserGreenroyd]

@BHoMBot this is a DevOps instruction. I am requesting neutral checks on: unit-tests

[bhombot-ci]

@FraserGreenroyd I have provided neutral checks to the checks requested. These checks will need to be run properly to obtain full results.

[FraserGreenroyd]

@BHoMBot check ready-to-merge

[bhombot-ci]

@FraserGreenroyd to confirm, the following actions are now queued:

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