ADD: "Remove all roles" button

frontend/src/views/netdb/Tokens.vue

@@ -56,6 +56,9 @@
                              sticky-header/>
                   </b-popover>
                 </template>
+                <b-button v-if="new_account.roles.length > 0" variant="outline-danger" block class="mt-1" @click="removeAllRoles">
+                  Alle Rollen entfernen
+                </b-button>
               </h5>
             </template>
           </b-form-group>
@@ -138,6 +141,9 @@
                            sticky-header/>
                 </b-popover>
               </template>
+              <b-button v-if="new_account.roles.length > 0" variant="outline-danger" block class="mt-1" @click="removeAllRoles">
+                Alle Rollen entfernen
+              </b-button>
             </h5>
           </b-form-group>
         </template>
@@ -568,6 +574,8 @@ export default {
         do_copy_roles: true,
         roles: []
       }
+      this.new_system = ''
+      this.new_role_name = ''
     },
     resetTokenData() {
       this.new_token = {
@@ -747,6 +755,10 @@ export default {
       }
       this.updateCanAddRole()
     },
+    removeAllRoles() {
+      this.new_account.roles = []
+      this.updateCanAddRole()
+    },
     updateCanAddRole() {
       const new_role = this.new_system + '.' + this.new_role_name
       if (!this.new_system || !this.new_role_name || !this.assignable_roles_by_fq_name[new_role]) {