Missing store_connection_channels after ExecutionContext refactor

[kevinji]

Bug Summary

The function

fn store_connection_channels(
    &mut self,
    connection_id: ConnectionId,
    port_id: PortId,
    channel_id: ChannelId,
) -> Result<(), ContextError>;

got removed during the ExecutionContext refactor, but

fn connection_channels(
    &self,
    connection_id: &ConnectionId,
) -> Result<Vec<(PortId, ChannelId)>, ContextError>;

remains in ValidationContext.

Details

Since store_connection_channels got removed from ExecutionContext, I think there isn't a function any more that ties connections to (port, channel) pairs anymore, meaning connection_channels would always return an error.

Version

ibc-rs v0.29.0 onwards.

[Farhad-Shabani]

It can still be retrieved by querying for all channels using ChannelEndPath and matching the passed connection_id with the connection_hops field of each found ChannelEnd. (like here in basecoin-rs).
Though indeed, it is not an efficient way and in some implementations can end up with the error.

[plafer]

I think the main point though is that it is no longer used by the core handlers, and so serves no purpose. So IIUC, we should just remove ValidationContext::connection_channels().