Sunrise / Sunset Time Offset

**Describe the problem you have/What new integration you would like**
When making an automaton using sunrise or sunset. it would be really great to have an offset option, so for example if i want the light in front of my house to go on 30 min before sunset.

The feature should allow for offsets above or below a sunrise / sunset time.

**Please describe your use case for this integration and alternatives you've tried:**
My use case is as mentioned above. The alternative is to use HA but ideally I would like to be as least reliant as possible.

**Additional context**
Home Assistant has this feature, so I assume it shouldn't be to difficult to port over.

The issue names no files, tests, or entry points. Start by locating the sunrise and sunset automation integration, then identify how event times are exposed and configured. Done means automations can apply positive or negative offsets to sunrise and sunset times, with coverage for both directions.

Written by the indexing model from the issue text.