[collector] Add support for VPA autoscaling

[zehenrique]

I would like to purpose VerticalPodAutoscaler support to the OpenTelemetry Collector helm chart.

Use cases:

• VPA recommendations are always useful for anyone managing an application. It helps you understand and set the right resource requests and limits for your workloads, which improves stability and cost efficiency.
• VPA auto mode would be especially helpful when running OTel Collector in StatefulSet mode since HPA autoscaling is only available in Deployment mode.

Would be more than happy to contribute and open a PR if the team thinks this is a useful feature.

[povilasv]

Question: How would it work with https://github.com/open-telemetry/opentelemetry-collector/blob/main/processor/memorylimiterprocessor/README.md ? I.e. Collector should start droping the data if it's close to its memory limit, so in theory it shouldnt go above the limit?

Would be cool to have this if it works well with that