fix: Stop popup editor from swallowing space key on Chromium

[enzi221]

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Summary

Fix Chromium users can't insert spaces in the popup editor.

Related Issues

None.

Changes

It seems that the current version of Monaco does NOT add contenteditable but uses EditContext API. This results in space keys not working at all in the popup editor.

Since its default hot key is Ctrl X, this is massively painful.

This PR adds another guard that is return 'editContext' in el && el.editContext != null. Verified working in Chrome (supports the API) and Firefox (does not support the API).

Impact

Usable popup editor.