Document usage of ' in events

[amaury1093]

Summary

We should explicity state that events require a '

Problem Definition

It's not clear whether we should do message.action=send or message.action='send'.

Before #8734, if we sent a gRPC request with message.action=send, the handler automatically added ' to convert to message.action='send'.

It has been removed in #8734, because it's probably more confusing than helpful. Tendermint always expect ', so we should just follow what TM does.

Proposal

• add additional validation to check ' in gRPC handlers
• verify docs
• add changelog for Move QueryTx functions to x/auth/tx #8734 (comment)

---

For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned