feat(evm) sibling cosmos lc (#2672)

Towards #2659 (we need to implement the second half on cosmwasm)

In this PR:

- we implements a Cosmos in Cosmos light client in EVM that will allow
any cosmos chain connected to union to have it's root hash committed on
EVM. This will allow direct connections/channels to EVM through Union.
- we extend the `ILightClient` interface to expose `isFrozen` for light
clients.
- we fix a Cometbls light client bug where we weren't checking whether
the client was frozen or not before checking membership proofs.
- we simplify the UCS01 contract and improve some tests (fuzz edge case
I found that were wrong as we were missing some `vm.assume`)