Add end-to-end test asserting protocol transactions are rejected when submitted via Tendermint

[james-chf]

anomac which we use for submitting transactions in our e2e tests is not able to send protocol transactions and probably it doesn't make sense for it to have that functionality, since in practice those should always be broadcast by validators running anoman. It would be useful to have a way to submit protocol transactions in another way for testing.

We can use TendermintWebsocketClient (although it is being deprecated) to build a protocol transaction in memory and submit it to the Tendermint RPC endpoint. We should already have the e2e test node validators' protocol keys available to us in the e2e tests.

This issue is motivated by anoma/anoma#1094 which needs this sort of functionality for testing.

[james-chf]

I put some functionality in https://github.com/anoma/devtool for submitting protocol transactions manually to a chain. End-to-end tests for submitting a protocol transaction to Tendermint are working for ABCI in anoma/anoma#1094. Submitting protocol transactions this way to modify the Ethereum bridge may not be applicable anymore in which case the generic functionality for submitting a protocol transaction within an e2e test can be factored out of that PR into a new PR if needed. There is a new Tendermint client coming in anoma/anoma#1088 that should be used in such tests instead of TendermintWebsocketClient

[james-chf]

No longer valid. We will accept certain protocol transactions via Tendermint, at least for the design of the Ethereum bridge that we will be using with Tendermint v0.37 (which doesn't have vote extensions).