Add optional annotations for zabbix-server service

[plicon]

What this PR does / why we need it:

Add optional annotations for zabbix-service. Can be used for requesting a specific ip-pool from metallb.

Which issue this PR fixes

• none, new feature

Special notes for your reviewer:

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• [x] DCO signed
• [x] Variables are documented in the README.md

[plicon]

Hi @aeciopires,

Just updated the version and ran helm-docs .. see commit … 4f62d80

[aeciopires]

Great job @plicon!

What do you think about making this same change for the zabbix-agent, zabbix-web and zabbix-proxy services?

In this case, the changes would be in this same PR... so I merge and generate the version with those changes all at once.

[plicon]

@aeciopires Sure and done! :)