expose Enable_Chunk_Trace in the crd, enabling TAP debuging

[danielpodwysocki]

implements #1586 closes #1586

This enables the users to turn debug traces on/off, as per https://docs.fluentbit.io/manual/administration/troubleshooting

I validate that I can spin up the operator and:

• enable/disable the option, it respects the SIGHUP&hot reload correcty
• see the expected result - I can now switch to a debug image and use the curl API to enable tracing

In my testing I used the following spec:

apiVersion: fluentbit.fluent.io/v1alpha2
kind: FluentBit
metadata:
  name: fluent-bit
  namespace: fluent
  labels:
    app.kubernetes.io/name: fluent-bit
spec:
  # renovate: datasource=docker depName=ghcr.io/fluent/fluent-operator/fluent-bit
  image: ghcr.io/fluent/fluent-operator/fluent-bit:4.0-debug
  fluentBitConfigName: fluent-bit-config

---
apiVersion: fluentbit.fluent.io/v1alpha2
kind: ClusterFluentBitConfig
metadata:
  name: fluent-bit-config
  namespace: fluent
  labels:
    app.kubernetes.io/name: fluent-bit
spec:
  service:
    enableChunkTrace: true
    httpServer: true
    httpListen: "127.0.0.1"
  inputSelector:
    matchLabels:
      fluentbit.fluent.io/enabled: "true"
  outputSelector:
    matchLabels:
      fluentbit.fluent.io/enabled: "true"

---
apiVersion: fluentbit.fluent.io/v1alpha2
kind: ClusterInput
metadata:
  name: dummy
  labels:
    fluentbit.fluent.io/enabled: "true"
spec:
  alias: dummy
  dummy:
    tag: my_dummy

---
apiVersion: fluentbit.fluent.io/v1alpha2
kind: ClusterOutput
metadata:
  name: stdout
  labels:
    fluentbit.fluent.io/enabled: "true"
spec:
  alias: stdout
  match: "*"
  stdout: {}

I could exec into the container and enable tracing with:

curl 127.0.0.1:2020/api/v1/trace/dummy

To disable it, I ran:

curl -X DELETE 127.0.0.1:2020/api/v1/trace/dummy

I saw the correct output reflected on fluentbit container log.

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

Does this PR introduced a user-facing change?

Additional documentation, usage docs, etc.:

[cw-Guo]

this is not in the document but i see it in the code: https://github.com/fluent/fluent-bit/blob/e8d608b7d7a7c12eae2dfce019f3c263257ed131/include/fluent-bit/flb_config.h#L370

[cw-Guo]

Thanks for the contribution! This is very helpful.