Abstract out the Board logic

[pedroCollogno]

Is your feature request related to a problem? Please describe.
Right now we only offer support for Trello boards. As we grow support for additional boards, we need to build an abstraction to the "Board" logic (ie: an interface), so that integrating new systems only requires building an adapter

Describe the solution you'd like

• Turn the TrelloHelper into a BoardHelper class that defines the contractual APIs we need to invoke.
• Port Trello to it as an example

[lorenzejay]

makes sense. I'd love to take a stab at this

[pedroCollogno]

Awesome @lorenzejay, super happy to review a PR when you have it :)

The actions we need can all be found here
Basically:

• creating a ticket and putting it in the Backlog with an assignee
• moving a ticket from one list to another (To Do -> WIP, WIP -> Ready for Review, Ready for Review -> Reviewed, Ready For Review -> Done)
• Retrieving a ticket assigned to X from the To Do list

the other ones we are not really using rn so it's ok to skip