Explore sending transaction via flashbots

[mmv08]

This feature request came from 1inch team that has a Safe app:

At 1inch Dapp we have the ability to send transactions through Flashbots (using current network RPC). But this feature is only available for wallets that are capable of signing transactions.
It is obviously that Gnosis has a different mechanism, so it would be cool if it was possible, when sending a transaction through Gnosis SDK, to specify how to send a transaction: through Flashbots or usually.

At first glance, it seems that to properly supports it, the Safe interface has to support flashbots natively, but ofc we can and should explore if it's possible to implement it in a different way