Support output level processors for Fluent Bit

[jeff303]

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

Fluent Bit supports specifying processors at the output level (see here). It would be great if support for this was added to Fluent Operator, so that we could propagate such processors at the CRD level.

Describe the solution you'd like

Add support for processor configuration under outputs, where applicable. It looks like this is only supported under YAML configuration, so #1008 would need to be done first.

[cw-Guo]

@jeff303 Just want to let you know, we have supported this feature via #1208