Linearize UDP packet filtering

[adriansmares]

Summary

Fixes https://the-things-industries.sentry.io/issues/5353455597

This PR makes the filtering of packets to be 'linear' for the same source address. This means that different source addresses are evaluated in parallel, but individual addresses (so gateways) are evaluated serially.

Changes

• Make the packet filtering linear for individual gateway addresses.
• Move the firewall filtering next to the rate limiting filtering and packet unmarshaling.
• Remove unused configuration options (which had no real effect after Improve Gateway Server throughput #7077).

Testing

Steps

This change has been tested on staging1 and other environments. As this is mainly technical debt and performance improvements, there are no manual testing steps to be done.

Results

Errors such as Failed to store updated rate limit data for key gs:up:udp:addr:x.x.x.x:y after 10 attempts are no longer encountered.

Regressions

N/A.

Checklist

• Scope: The referenced issue is addressed, there are no unrelated changes.
• Compatibility: The changes are backwards compatible with existing API, storage, configuration and CLI, according to the compatibility commitments in README.md for the chosen target branch.
• Documentation: Relevant documentation is added or updated.
• Testing: The steps/process to test this feature are clearly explained including testing for regressions.
• Infrastructure: If infrastructural changes (e.g., new RPC, configuration) are needed, a separate issue is created in the infrastructural repositories.
• Changelog: Significant features, behavior changes, deprecations and fixes are added to CHANGELOG.md.
• Commits: Commit messages follow guidelines in CONTRIBUTING.md, there are no fixup commits left.