Add support PriorityClass for target-allocator Pod

[mdietzer-fn]

Component(s)

target allocator

Is your feature request related to a problem? Please describe.

We would like to set a PriorityClass for all of our OpenTelemetry Pods. Most pods objects/configs support this via priorityClassName. However, the TargetAllocator spec does not seem to include priorityClassName as a possible field.

Setting priorityClassName on an opentelemetry.io/v1beta1:OpenTelemetryCollector gives the collector itself the priority class, but if the targetAllocator is enabled within this object, it does not inherit this priority class, so there is no way to configure it.

Describe the solution you'd like

Add priorityClassName to the target allocator spec such that it can have a priority class configured or inherit priority class from the main OpenTelemetryCollector object.

Describe alternatives you've considered

No response

Additional context

No response

[swiatekm-sumo]

Rather than add new fields to the embedded target allocator subresource in the OpenTelemetryCollector CR, we want to introduce a separate TargetAllocator CRD, which would have the same infrastructure related fields OpenTelemetryCollector has. The reason for this is that the collector CR is already quite big, and doubling all of these fields will make it even more so, which leads to various problems.

See #2422 for progress.