What does this implement/fix?

See title. Relevant for debugging/tracing down DHCP issues with a much lower entrance barrier compared to running Wireshark capturing on a remote device (when your Pi-hole is a headless system).

This option default to false and be activated as any other config option, too, via

• the API, or
• the CLI (like sudo pihole-FTL --config dhcp.logging true), or
• direct interaction with /etc/pihole/pihole.toml, or
• by importing a teleporter file where this is already active.

Related issue or feature (if applicable): See Discourse thread mentioned below.

Pull request in docs with documentation (if applicable): N/A

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1. I have read and understood the contributors guide, as well as this entire template. I understand which branch to base my commits and Pull Requests against.
2. I have commented my proposed changes within the code.
3. I am willing to help maintain this change if there are issues with it later.
4. It is compatible with the EUPL 1.2 license
5. I have squashed any insignificant commits. (git rebase)

Checklist:

• The code change is tested and works locally.
• I based my code and PRs against the repositories developmental branch.
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• I have read the above and my PR is ready for review.