Keyboard shortcuts can be modified through the shortcut panel and are stored in localstorage

[om-ray]

What does this pull request do?

Some browsers had claimed the default shortcuts used in the app, this caused problems for some users when they were using the app. This pull request makes it so that the user can change the keyboard shortcuts to anything they want through the shortcut panel (https://github.com/jsonhero-io/jsonhero-web/pull/67) by hovering over the icons in the panel and typing in the key combination they want. The app will automatically generate the needed icons for any letters, with icons for keys like Cmd, Control, Shift, Alt.etc already in the app.

The following is a Loom video showing how the custom keyboard shortcuts work: https://www.loom.com/share/84e2cb09b21f42218c0d72d0f29170f9

@samejr