Investigate indexing options for recovery proposals

[iamacook]

The web is currently using RPC calls to retrieve recovery proposals. This is both costly and inefficient, with some chains not supporting the implementation.

We should investigate the options available for indexing (e.g. The Graph) to instead include said proposals in the transaction queue.

As each module is deployed per Safe so we would need need to index ModuleProxyCreation events of Zodiac's ModuleProxyFactory contract and then the TransactionAdded events of each Delay modifier.

Grouping recovery attempts and their cancellations

This logic is currently also on the frontend. It finds a cancellation transaction (which is a regular Safe tx, a contract call) in the queue, and visually groups it with the corresponding recovery. This results in cancellations being displayed in two places – regular queue and pending recovery queue.

This logic should be moved to CGW and handled holisitcally.