Auto merge of #15495 - prampey:mql-borrow-error, r=jdm

Calling matchMedia during a MQL change event will not panic

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Calling matchMedia now leads to a new copy of MQL objects to prevent errors when borrowing references from MQL during an MQL change event.

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #14967  (github issue number if applicable).

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