Support mirroring request body

Co-authored-by: Mathieu Lonjaret <mathieu.lonjaret@gmail.com>
Co-authored-by: Julien Salleyron <julien.salleyron@gmail.com>

docs/content/reference/dynamic-configuration/file.toml

@@ -65,6 +65,7 @@
     [http.services.Service02]
       [http.services.Service02.mirroring]
         service = "foobar"
+        maxBodySize = 42
 
         [[http.services.Service02.mirroring.mirrors]]
           name = "foobar"

docs/content/reference/dynamic-configuration/file.yaml

@@ -72,6 +72,7 @@ http:
     Service02:
       mirroring:
         service: foobar
+        maxBodySize: 42
         mirrors:
         - name: foobar
           percent: 42

docs/content/reference/dynamic-configuration/kubernetes-crd-resource.yml

@@ -65,6 +65,8 @@ spec:
     kind: TraefikService
     mirrors:
       - name: s2
+        # Optional
+        maxBodySize: 2000000000
         # Optional, as it is the default value
         kind: Service
         percent: 20

docs/content/reference/dynamic-configuration/kv-ref.md

@@ -174,6 +174,7 @@
 | `traefik/http/services/Service01/loadBalancer/sticky/cookie/httpOnly` | `true` |
 | `traefik/http/services/Service01/loadBalancer/sticky/cookie/name` | `foobar` |
 | `traefik/http/services/Service01/loadBalancer/sticky/cookie/secure` | `true` |
+| `traefik/http/services/Service02/mirroring/maxBodySize` | `42` |
 | `traefik/http/services/Service02/mirroring/mirrors/0/name` | `foobar` |
 | `traefik/http/services/Service02/mirroring/mirrors/0/percent` | `42` |
 | `traefik/http/services/Service02/mirroring/mirrors/1/name` | `foobar` |