Add Script Panel Shortcuts

[Cuperino]

• feat: Add New, Open, and Save shortcuts to Script Panel
• fix: Check whether script needs to be saved before opening a new one

[narnaud]

It would be better to add shrtucts to the ScriptPanel::ScriptPanel.
This way the shortcuts will be visible on hover (better for discoverability).

The only problem will be to handle the same shortcuts multiple time, I can't remmeber if Qt do that nicely by derfault. Another option will be to use Ctrl+Alt+Foo for example.

[Cuperino]

I like the idea of handling them from ScriptPanel::ScriptPanel. Need to look how that would be done without creating conflicting bindings. In QML one can have one event handling function call another, effectively forwarding events conditionally.

I wouldn't go for Ctrl+Alt+Foo because that would go against muscle memory. Standard binding outcomes should adapt according on the context.