eth-json-rpc-provider: Remove deprecated methods `send` and `sendAsync`

[rekmarks]

We should remove the deprecated send and sendAsync methods from the InternalProvider. The reason they're still around is to maintain compatibility with the InternalProvider and libraries like eth-query / ethjs-query. Consequently, we need to audit our dependencies that consume the InternalProvider for use of send and sendAsync, remove the usage from our forks of said dependencies, replace any third-party dependencies that can't be fixed, and then finally remove the methods, leaving only InternalProvider.request() (as is expected by e.g. ethers).