Send should revert if the gas limit has not been set for a destination chain (peer)
Description
send() allows users to send messages with 0 gas limit if the gasLimit mapping has not be seen for a certain peer. This will likely make the transaction revert on the destination chain, losing the funds.
POC here.
Recommendation
Revert if trying to send a message to _dstEid whose gas limit was not yet set.
Status
Addressed in 98f36e9.