Proposing structured field overrider API

[RainbowMango]

What type of PR is this?

/kind api-change

What this PR does / why we need it:
This PR proposes the API change to address the requirement of #5449.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:
For example, if you want to modify the database's host and port in the following ConfigMap:

apiVersion: v1
kind: ConfigMap
metadata:
  name: example-config
data:
  db-config.yaml: |
    database:
      host: localhost
      port: 3306

You can do that by leveraging the proposing API:

apiVersion: karmada.io/v1alpha1
kind: OverridePolicy
metadata:
  name: example-configmap-override
spec:
  resourceSelectors:
    - apiVersion: v1
      kind: ConfigMap
      name: example-config
  overrideRules:
    - targetCluster: {}
      overriders:
        fieldOverrider:
          - fieldPath: /data/db-config.yaml
            yaml:
              - subPath: /database/host
                operator: replace
                value: "remote-db.example.com"
              - subPath: /database/port
                operator: replace
                value: "3307"

The OverridePolicy declares the replace the /database/host with remote-db.example.com and port with 3307.

The expected result should be:

apiVersion: v1
kind: ConfigMap
metadata:
  name: example-config
data:
  db-config.yaml: |
    database:
      host: remote-db.example.com
      port: 3307

Does this PR introduce a user-facing change?:

API Change: Introduced `FieldOverrider` to both OverridePolicy and ClusterOverridePolicy, which provides the ability to override structured data nested in manifest like ConfigMap or Secret.

[sophiefeifeifeiya]

The API looks good. btw, overriders needs to be added.

apiVersion: karmada.io/v1alpha1
kind: OverridePolicy
metadata:
  name: example-configmap-override
spec:
  resourceSelectors:
    - apiVersion: v1
      kind: ConfigMap
      name: example-config
  overrideRules:
    - overriders:
        fieldOverrider:
          - fieldPath: /data/db-config.yaml
            yaml:
              - subPath: /database/host
                operator: replace
                value: "remote-db.example.com"
              - subPath: /database/port
                operator: replace
                value: "3307"

[RainbowMango]

Thanks. Updated.

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Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5581      +/-   ##
==========================================
- Coverage   34.87%   34.86%   -0.01%     
==========================================
  Files         645      645              
  Lines       44833    44833              
==========================================
- Hits        15637    15633       -4     
- Misses      27991    27994       +3     
- Partials     1205     1206       +1     

Flag	Coverage Δ
unittests	34.86% <ø> (-0.01%)	⬇️

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[RainbowMango]

Given our decision on #5449, we can now move this forward.

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