[Scenario] Actions editor follow-ups

[PankajBhojwani]

Description of the new feature

Collection of follow ups for v2 of the actions editor

Unimplemented shortcut actions

• MultipleActions
• ColorSelection
• Changing the type of a new tab/new window/split pane action to open a non-terminal tab/window/pane (eg. snippets pane)

QOL

• Add validation to the arguments that need them (eg. an empty Input field on a SendInput action should display a warning)
• "Clone action" button
• Searchbox for the shortcut action list
• Show more than just the first keybinding on the top level actions page