Programmatic API to communicate deck tool instance

[RillingDev]

For further integrations, it will be required for other JS code to communicate with a running deck tool instance. It must be possible to retrieve deck contents and react to changes to the deck.

API

A global field yugiohDeckTool is exposed on window.

It has a method to get a frozen copy of the current deck state:

window.yugiohDeckTool.getDeck() // Returns deck format as stored internally

it publishes events when deck changes are made:

window.yugiohDeckTool.on("change", ()=>{}) // Called whenever *any* change is made to the deck

Ideas

• possibly check current usage of window and unify.

[RillingDev]

a2dfb92