Implement ProxySettingsPolicy (#4286)

Problem: We need to implement the ProxySettingsPolicy API

Solution: Implement ProxySettingsPolicy

Manual Testing: Tested using the example files provided which will be the basis of the documentation:
Steps (using the provided examples):

Deploy an application which returns a large payload (coffee) and one which does not (tea)
Apply the PSP for the Gateway which will support the smaller payload application
Verify tea works but coffee does not (response too large error in NGINX logs)
Apply the PSP for the coffee route which increases the proxy buffer size
Verify coffee now works (note: return output to file if testing this as it fills the terminal)

Author: ciarams87

.yamllint.yaml

@@ -29,6 +29,7 @@ rules:
     check-multi-line-strings: true
     ignore: |
       operators/**/*
+      examples/proxy-settings-policy/app.yaml
   key-duplicates: enable
   key-ordering: disable
   line-length:

charts/nginx-gateway-fabric/templates/clusterrole.yaml

@@ -129,6 +129,7 @@ rules:
   - clientsettingspolicies
   - observabilitypolicies
   - upstreamsettingspolicies
+  - proxysettingspolicies
   {{- if .Values.nginxGateway.snippetsFilters.enable }}
   - snippetsfilters
   {{- end }}
@@ -142,6 +143,7 @@ rules:
   - clientsettingspolicies/status
   - observabilitypolicies/status
   - upstreamsettingspolicies/status
+  - proxysettingspolicies/status
   {{- if .Values.nginxGateway.snippetsFilters.enable }}
   - snippetsfilters/status
   {{- end }}

deploy/azure/deploy.yaml

@@ -169,6 +169,7 @@ rules:
   - clientsettingspolicies
   - observabilitypolicies
   - upstreamsettingspolicies
+  - proxysettingspolicies
   verbs:
   - list
   - watch
@@ -179,6 +180,7 @@ rules:
   - clientsettingspolicies/status
   - observabilitypolicies/status
   - upstreamsettingspolicies/status
+  - proxysettingspolicies/status
   verbs:
   - update
 - apiGroups:

deploy/default/deploy.yaml

@@ -169,6 +169,7 @@ rules:
   - clientsettingspolicies
   - observabilitypolicies
   - upstreamsettingspolicies
+  - proxysettingspolicies
   verbs:
   - list
   - watch
@@ -179,6 +180,7 @@ rules:
   - clientsettingspolicies/status
   - observabilitypolicies/status
   - upstreamsettingspolicies/status
+  - proxysettingspolicies/status
   verbs:
   - update
 - apiGroups:

deploy/experimental-nginx-plus/deploy.yaml

@@ -171,6 +171,7 @@ rules:
   - clientsettingspolicies
   - observabilitypolicies
   - upstreamsettingspolicies
+  - proxysettingspolicies
   verbs:
   - list
   - watch
@@ -181,6 +182,7 @@ rules:
   - clientsettingspolicies/status
   - observabilitypolicies/status
   - upstreamsettingspolicies/status
+  - proxysettingspolicies/status
   verbs:
   - update
 - apiGroups:

deploy/experimental/deploy.yaml

@@ -171,6 +171,7 @@ rules:
   - clientsettingspolicies
   - observabilitypolicies
   - upstreamsettingspolicies
+  - proxysettingspolicies
   verbs:
   - list
   - watch
@@ -181,6 +182,7 @@ rules:
   - clientsettingspolicies/status
   - observabilitypolicies/status
   - upstreamsettingspolicies/status
+  - proxysettingspolicies/status
   verbs:
   - update
 - apiGroups:

deploy/inference-nginx-plus/deploy.yaml

@@ -169,6 +169,7 @@ rules:
   - clientsettingspolicies
   - observabilitypolicies
   - upstreamsettingspolicies
+  - proxysettingspolicies
   verbs:
   - list
   - watch
@@ -179,6 +180,7 @@ rules:
   - clientsettingspolicies/status
   - observabilitypolicies/status
   - upstreamsettingspolicies/status
+  - proxysettingspolicies/status
   verbs:
   - update
 - apiGroups:

deploy/inference/deploy.yaml

@@ -169,6 +169,7 @@ rules:
   - clientsettingspolicies
   - observabilitypolicies
   - upstreamsettingspolicies
+  - proxysettingspolicies
   verbs:
   - list
   - watch
@@ -179,6 +180,7 @@ rules:
   - clientsettingspolicies/status
   - observabilitypolicies/status
   - upstreamsettingspolicies/status
+  - proxysettingspolicies/status
   verbs:
   - update
 - apiGroups:

deploy/nginx-plus/deploy.yaml

@@ -169,6 +169,7 @@ rules:
   - clientsettingspolicies
   - observabilitypolicies
   - upstreamsettingspolicies
+  - proxysettingspolicies
   verbs:
   - list
   - watch
@@ -179,6 +180,7 @@ rules:
   - clientsettingspolicies/status
   - observabilitypolicies/status
   - upstreamsettingspolicies/status
+  - proxysettingspolicies/status
   verbs:
   - update
 - apiGroups:

deploy/nodeport/deploy.yaml

@@ -169,6 +169,7 @@ rules:
   - clientsettingspolicies
   - observabilitypolicies
   - upstreamsettingspolicies
+  - proxysettingspolicies
   verbs:
   - list
   - watch
@@ -179,6 +180,7 @@ rules:
   - clientsettingspolicies/status
   - observabilitypolicies/status
   - upstreamsettingspolicies/status
+  - proxysettingspolicies/status
   verbs:
   - update
 - apiGroups: