Add PreUp, PostUp, PreDown, PostDown for client (#1714)

* Fix create client popup background is not white

* Fix no Add button when client Allowed Ips or Server Allowed Ips is empty

* Add preUp preDown postUp postDown for client

* Add description of hooks for client config

* Move hooks's label text into 'hooks' in en.json

---------

Co-authored-by: yanghuanglin <yanghuanglin@qq.com>
Co-authored-by: Bernd Storath <999999bst@gmail.com>

src/app/pages/clients/[id].vue

@@ -71,6 +71,35 @@
               :label="$t('general.persistentKeepalive')"
             />
           </FormGroup>
+          <FormGroup>
+            <FormHeading :description="$t('client.hooksDescription')">
+              {{ $t('client.hooks') }}
+            </FormHeading>
+            <FormTextField
+              id="PreUp"
+              v-model="data.preUp"
+              :description="$t('client.hooksLeaveEmpty')"
+              :label="$t('hooks.preUp')"
+            />
+            <FormTextField
+              id="PostUp"
+              v-model="data.postUp"
+              :description="$t('client.hooksLeaveEmpty')"
+              :label="$t('hooks.postUp')"
+            />
+            <FormTextField
+              id="PreDown"
+              v-model="data.preDown"
+              :description="$t('client.hooksLeaveEmpty')"
+              :label="$t('hooks.preDown')"
+            />
+            <FormTextField
+              id="PostDown"
+              v-model="data.postDown"
+              :description="$t('client.hooksLeaveEmpty')"
+              :label="$t('hooks.postDown')"
+            />
+          </FormGroup>
           <FormGroup>
             <FormHeading>{{ $t('form.actions') }}</FormHeading>
             <FormActionField type="submit" :label="$t('form.save')" />