fix: Reduce logging severity of certain errors

Here are the proposed changes:
- OverflowedJsonInteger: exception -> debug
- InvalidJson: exception -> debug
- InvalidQueueName: warning -> debug

Rationale: these pollute the server logs and provide little value to
system operators.

Change-Id: Icd73a5bd3fc7d7ef349b18e7e485df8a7dfc0a1a
Closes-Bug: #1246977
Merge "fix: Reduce logging severity of certain errors"