Look into more intuitive ways to sign malleated transactions

[evan-forbes]

Currently, we use the KeyringSigner to programmatically sign malleated transactions. This is because the standard cosmos-sdk tx.Factory does not support creating multiple malleated transactions and then signing over those as well. We might be able to refactor KeyringSigner so that it's more intuitive.

[tac0turtle]

This is a code smell imo. Duplicating code from the sdk and then seeing comments like

// makeEncodingConfig is copied here so that we don't have to have an
//  import cycle. if possible, use cosmoscmd.MakeEncodingConfig

make me a bit worried that the design is incorrect.

would be nice to remove the testutil/network.go setup as well. Customising the app breaks this because its not automatic in how the app is set up.

[evan-forbes]

closing as this is a duplicate of #294, which we will finally be able to handle now that we can simplify the malleation process using square size independent commitments