PR summary

Possibly closes #30230, though I'm unsure if it's a bit too hacky.

Introduce new private attributes so that apply_aspect can keep track of the previously set x/y-bounds. These attributes get reset when set_xlim/set_ylim are called, so further user updates to the limits are respected.

I ran the code from #30230 (comment) and messed about with the window shape. Everything seems fine.

If this seems good to others, I will add a test.

PR checklist

• "closes #0000" is in the body of the PR description to link the related issue
• new and changed code is tested
• [n/a] Plotting related features are demonstrated in an example
• [n/a] New Features and API Changes are noted with a directive and release note
• [n/a] Documentation complies with general and docstring guidelines