[processor/tailsampling] Deprecate invert sample decisions

[portertech]

Description

Users can now use the newly added Drop policy type to explicitly drop (not sample) specific traces regardless of other policy decisions. This pull-request deprecates the invert sample decisions.

This pull-request introduces a feature gate/flag, processor.tailsamplingprocessor.disableinvertsample, to disable the invert sample decisions. The gate/flag influences the underlying policy evaluation for simplicity. With the gate/flag enabled, the string, numeric, and boolean filter policies still support invert_match, which continues to flip the decision for the individual policy (only Sampled and NotSampled). Letting invert_match be simple.

Related Issues

• [processor/tailsampling] Allow invert matches in composite policy to continue processing #36673
• [processor/tailsampling] invert_match not given precedence when inside and policy #33656
• Tail-based sampling with policies evaluated with first match mechanism #36795
• [processor/tailsampling] numeric attribute invert match evaluation not prioritized #34296
• [processor/tailsampling] invert_match precedence  #34085
• Unexpected behavior of And policy #29637
• Tail-sampling evaluation completing but not filtering out any traces for Grafana Tempo Distributed  #27049
• Probably more 😅

TODO

• Log deprecation warning
• Document the deprecation
• Document the feature gate/flag