register processor per handler and per channel
feature #3841 [Cookbook][Logging] register processor per handler and per channel (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
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[Cookbook][Logging] register processor per handler and per channel

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | #3798

Commits
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8a83649 register processor per handler and per channel