Use Google's Protobuf well-known types definitions instead of prost_types

[stevenatcrypto]

According to this recent PR of ibc-rs, should we also use Google's Protobuf well-known types definitions instead of prost_types to derive Serialize and Deserialize? Thanks.

[tony-iqlusion]

This feels like something that needs to be changed in tendermint-rs/tendermint-proto first, and we can follow suit. Otherwise we can't interop with their protos.

[tony-iqlusion]

Here's an upstream issue on tendermint-rs: informalsystems/tendermint-rs#1053

I'd suggest any further discussion happens there. The crates in this repo will adopt whatever solution is used upstream.