Upgrade to Open WebUI 0.2+, Add Pipelines Integration

[0xThresh]

This PR upgrades Open WebUI to v0.2+, and adds an integration for Pipelines. It also fixes a bug with the Ollama service name not populating correctly with the integrated Ollama chart, updates the Ollama chart version, and adds new documentation.

Closes:

• https://github.com/open-webui/helm-charts/issues/19
• https://github.com/open-webui/helm-charts/issues/27