[TxPool] Fix double nonce in promoted

[dbrajovic]

Fix EDGE-813

Description

This PR fixes the issue of transactions sharing nonce ending up in promoted queue of an account.

Changes include

• Bugfix (non-breaking change that solves an issue)
• Hotfix (change that solves an urgent issue, and requires immediate attention)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)

Breaking changes

Please complete this section if any breaking changes have been made, otherwise delete it

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have added the relevant labels
• I have updated the official documentation
• I have added sufficient documentation in code

Testing

• I have tested this code with the official test suite
• I have tested this code manually

Manual tests

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Documentation update

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Additional comments

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Codecov Report

❗ No coverage uploaded for pull request base (release/0.5.1@06d3f72). Click here to learn what that means.
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[dbrajovic]

I can't approve this (since I opened the PR).

LGTM 👍

[zivkovicmilos]

Lookin' good 💯

[0xAleksaOpacic]

LGTM!