`cadvisor/utils/oomparser` - Add constructor to (optionally) allow streaming of current+new OOMs only.

### Summary

`cadvisor/utils/oomparser` currently returns an `OomParser` object with the underlying reader pointing to the head of `/dev/kmsg`. This returns _all_ OOM events that are currently available in the kmsg buffer.

While this is desirable in certain cases, a user may wish to only subscribe to _new_ OOM events that are occurring. The underlying reader supports a [SeekEnd](https://github.com/euank/go-kmsg-parser/blob/v3.0.0/kmsgparser/kmsgparser.go#L122-L125) function that fast-forwards the offset to the end of the buffer.

This is a request to add a constructor that returns the `OomParser` object with the offset moved to the end of the kmsg queue.