unifi-poller: add service and prometheus-exporter

[elseym]

Motivation for this change

• adds unifi-poller package and module closely resembling the unifi-poller config-structure
• adds a tested prometheus-exporter module
• can be used together with the old prometheus-exporter
• should resolve Replace unifi_exporter with unifi-poller (prometheus exporter) #88846

also:

• extends the prometheus-exporters tests to handle hyphenated exporter-names (by overriding the name of the testnode)

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS (just the package)
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[elseym]

oh well. didn't see #95994.
@bachp interested in merging our efforts?

[lheckemann]

Some changes I'd suggest, overall LGTM :)

[elseym]

@lheckemann thanks for the pointers. 🙂 i'll update the pr tomorrow.

[aanderse]

I'm not familiar with this software - I just want to mention that we shouldn't have any password options, only passwordFile like options please.

[lheckemann]

While a little refactoring on the prometheus exporters side wouldn't be amiss (in order to allow the warnings to apply to prometheus-exporter use, not just standalone use of the poller), I think blocking this addition on said refactoring wouldn't make much sense.

I'm happy with how the other points have been addressed, so I'd be all for merging it — @aanderse is that alright with you?

[aanderse]

Without understanding the software itself module LGTM 👍

[elseym]

thanks for all your help.
the modules now only allow password files and provide the default passwords via writeText. i chose not to use the option name passwordFile but rather keep pass to minimise juggling with the generated json data and keep the modules more maintainable. the provided descriptions and option types should make the usage clear enough.