Support localhost client/connection in conformance test

[migueldingli1997]

Closes #670

Quite a quick-and-dirty fix, if I'm being honest. Open to other ways of tackling this.

[migueldingli1997]

I've just noticed that the scope of this is a bit larger than I expected, since interchaintest also makes use of an old version of the Go relayer, which does not seem to be compatible with the localhost client either.

[boojamya]

Hey @migueldingli1997, this fix looks good to me.
But you're right, we still need a relayer that has localhost support. Without it, I'm seeing this error:

"no concrete type registered for type URL /ibc.lightclients.localhost.v2.ClientState against interface *exported.ClientState"

We plan to cut a relayer release this week.
Then we can update the relayers DefaultContainerVersion in cosmos_relayer.go.

I've confirmed that conformance will pass with a relayer that supports localhost with this matrix file:

{
  "Relayers": ["rly"],

  "ChainSets": [
    [
      {
        "Name": "ibc-go-simd",
        "Version": "v7.2.0"
      },
      {
        "Name": "ibc-go-simd",
        "Version": "v7.2.0"
      }
    ]
  ]
}

Thanks for the PR, we'll get this merged soon.

[gjermundgaraba]

Btw: just tested this change with the latest version of rly (2.4.0) and it works for IBC 7.2 with localhost client. Would love to see this merged with the latest version of rly included 🙏