feat: Open Webui Pipelines service and integration with Open WebUI frontend

[ic4l4s9c]

Initial support for Open WebUI Pipelines and integration with Open WebUI frontend. Following wiki:

Added service files:

• compose.pipelines.yml — Docker Compose Pipelines service definitions.
• compose.x.webui.pipelines.yml — Docker Compose cross-service file for integration with Open WebUI Frontend.

Added configuration files:

• open-webui/configs/config.pipelines.json — WebUI Frontend config for connecting to Pipelines API.

Added environment variables override file:

• pipelines/override.env

Miscellaneous:

• Service environment variables added to profiles/default.env
• Service listed in README.md
• Refactored Services/Satellites section in README.md for better readability on small screens (please consider my changes, if not let me know, I'll revert it to original formatting)
• Service directory added to .gitignore

Please let me know if additions or changes needed.

[av]

Added the docs here: https://github.com/av/harbor/wiki/2.3.25-Satellite:-Open-WebUI-Pipelines

Thanks again!

[ic4l4s9c]

It's probably my mistake for adding section for pipelines default variables not at the end of the profiles/default.env, but after 4604e6a there is a collision in port mapping between HARBOR_PIPELINES_HOST_PORT and HARBOR_CHATNIO_HOST_PORT.

[av]

Thanks for pointing this out! Resolved in latest main by shifting chatnio main port to 34219 (lazy but allows to only update a single wiki entry)