Add to General Settings transaction fee preferences based on transaction type

[lautome]

Hi,

Use case: Not each transaction type needs the same processing speed. Signing a DAO vote or staking a LP does not require the same urgency as a swap. As Rabby is using DeBank's database to recognize the various smart contracts with whom most users interact it would be nice to specify in Rabby's general settings how fast certain transactions have to be treated by default.

For example: Staking/unstaking a LP: Standard Swaping: Fast

Of course, when presented with Rabby's transaction popup the user should be able to still select another gas setting.

Rabby is a fantastic tool, many thanks for developing it.