[Proxy colonies M1] feat: implement saga to add proxy colony via permissions

[bassgeta]

Specification

Story

As a user moderating a colony, I want to be able to add a new proxy colony on a supported chain.

Description

NOTE: In order for this to work properly, we need #3768 done first. The proxy colony isn't truly deployed until that event is emitted on the proxy chain. We need to create a temporary UI which call the saga that will create a proxy colony and create a transactions. The block ingestor needs to pick that up when it's created and save it in the database. Additionally since this is an action, we need to implement a new action type ADD_PROXY_COLONY and create an entry in the database.

Implementation

This issue is complete when...

• [ ] The temporary UI calls the addSupportedChain saga which creates a new transaction, creating a new proxy colony
• [ ] The block ingestor is able to catch that event and save the new proxy colony entry + create the action in the database

[rdig]

@bassgeta can you add a rough estimate for this ?