Research on how to make it easier to add new networks

[tschubotz]

Problem to solve

#476

Requirements

• Evaluate how to make it easier to self-host the Safe infrastructure
• Improve documentation.
• Evaluate building an Safe L2 interface which only works with events, i.e. which only requires an RPC endpoint and which does not require our full-fledged backend.
• Explore integration of non-Gnosis hosted networks in the UI (While making it clear in the UI)
• Evaluate and fix performance bottlenecks on our side as much as possible.
• Come up with an implementation plan for Q4