params: fix bor key-value config look-up

[yperbasis]

Description

This PR fixes 3 issues:

1. calculateBorConfigHelper, previously used by CalculateBackupMultiplier & CalculatePeriod incorrectly returned the very last entry for block numbers that matched exactly a key in the map. Practically, it only affected Mumbai since BorMainnet has a single entry in the BackupMultiplier & Period maps.
2. CalculateBurntContract, used for the upcoming Agra fork, would've suffered from the same issue.
3. Lexicographic instead of numerical ordering, previously used in borKeyValueConfigHelper, can lead to bugs with blocks like 90M vs 100M (90,000,000 < 100,000,000, but lexicographically "90000000" > "100000000")

Changes

• 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)
• Changes only for a subset of nodes

Breaking changes

Mumbai-only: CalculateBackupMultiplier(25275000) & CalculatePeriod(25275000) now correctly return 5 instead of 2.

Testing

• I have added unit tests
• I have added tests to CI
• I have tested this code manually on local environment
• I have tested this code manually on remote devnet using express-cli
• I have tested this code manually on mumbai
• I have created new e2e tests into express-cli

[codecov]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Files	Coverage Δ
params/config.go	36.56% <68.75%> (+11.24%)	⬆️

... and 42 files with indirect coverage changes

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