fix: close window when leave fullscreen crash

[codebytere]

Description of Change

Closes #25422.

Previously we emitted the event before calling web_contents(), which meant if an event callback destroyed or closed a window, then OnWindowLeaveFullScreen() would crash because the webContents would be gone. This handles that by moving the event emission beneath the web_contents() logic on macOS.

cc @MarshallOfSound @jkleinsc @zcbenz

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• PR title follows semantic commit guidelines
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Fixed a crash when closing window in an event listener after exiting fullscreen on macOS.

[release-clerk]

Release Notes Persisted

Fixed a crash when closing window in an event listener after exiting fullscreen on macOS.

[trop]

I was unable to backport this PR to "10-x-y" cleanly;
you will need to perform this backport manually.

[trop]

I have automatically backported this PR to "11-x-y", please check out #25524

[trop]

I was unable to backport this PR to "9-x-y" cleanly;
you will need to perform this backport manually.

[trop]

@codebytere has manually backported this PR to "10-x-y", please check out #25604

[trop]

@codebytere has manually backported this PR to "9-x-y", please check out #25605