[ibc-client-tendermint-types] properly handle fallible conversion between prost Duration and core Duration

[rnbguy]

Bug Summary

This PR informalsystems/tendermint-rs#1456 makes the conversion between tendermint-rs's auto-compiled Google's Duration and core::time::Duration fallible in both direction.

Because of this, our From<DomainClientState> for ProtoClientState pattern fails for Tendermint light client state implementations.

Details

The below is the current fix for Tendermint light client fields which use Duration type.

ibc-rs/ibc-clients/ics07-tendermint/types/src/client_state.rs

Lines 323 to 325 in 81625d6

	trusting_period: value.trusting_period.try_into().ok(),
	unbonding_period: value.unbonding_period.try_into().ok(),
	max_clock_drift: value.max_clock_drift.try_into().ok(),

Ideally, the following implementation

ibc-rs/ibc-clients/ics07-tendermint/types/src/client_state.rs

Line 317 in 81625d6

impl From<ClientState> for RawTmClientState {

should be refactored to,

impl TryFrom<ClientState> for RawTmClientState

with

 trusting_period: Some(value.trusting_period.try_into()?), 
 unbonding_period: Some(value.unbonding_period.try_into()?), 
 max_clock_drift: Some(value.max_clock_drift.try_into()?),

For this, we need a refactor of Protobuf trait in tendermint-rs repo -- which should use TryFrom<Self>.

pub trait Protobuf<T: Message + TryFrom<Self> + Default>
where ...

Version