Missing coin denomination in logs

[skeremidchiev]

Summary of Bug

Methods CreateValidator(), Delegate(), BeginRedelegate(), Undelegate() from msgServer in x/staking/keeper/msg_server.go emit incorrect event with missing coin denomination part.

For example instead of having an attribute inside logs with this data:
{"key":"amount","value":"45856uphoton"}
Logs currently contain:
{"key":"amount","value":"45856"}

Version

cosmos-sdk v0.43.0-rc2

Steps to Reproduce

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