[compatible] Fix a few bugs in revalidate (mini)

[georgeee]

Twin of #16401 against compatible

1. Fix two similar issues originating from confusion between previous variable names t and t' (Account no longer has permission to send and Current account nonce precedes first nonce in queue)
2. Fix the issue multiple nodes crashed #16397 by ensuring removal from applicable_by_fee is
   done only for the previous head of queue.

Explain how you tested your changes:

• Increase test coverage for transaction pool module #16415 unit tests

Checklist

• Dependency versions are unchanged
  • Notify Velocity team if dependencies must change in CI
• Modified the current draft of release notes with details on what is completed or incomplete within this project
• Document code purpose, how to use it
  • Mention expected invariants, implicit constraints
• Tests were added for the new behavior
  • Document test purpose, significance of failures
  • Test names should reflect their purpose
• All tests pass (CI will check this if you didn't)
• Serialized types are in stable-versioned modules
• Does this close issues? List them

• Closes multiple nodes crashed #16397

[mergify]

⚠️ The sha of the head commit of this PR conflicts with #16401. Mergify cannot evaluate rules on this PR. ⚠️

[mrmr1993]

This PR now represents an empty diff. Closing.