Add confirmation for ban/make admin etc

Also, fix Firefox problem with dialog jumping around.

src/components/ConfirmationDialog.vue

@@ -0,0 +1,37 @@
+<template>
+  <v-dialog
+    v-bind="{ ...$props }"
+    class="ma-0 pa-0"
+    :width="$vuetify.display.smAndUp ? '688px' : '95%'"
+    scroll-strategy="none"
+    @click:outside="$emit('update:modelValue', false)"
+  >
+    <v-card>
+      <v-card-text class="pa-4 black--text">{{ message }}</v-card-text>
+      <v-card-actions class="pt-3">
+        <v-spacer></v-spacer>
+        <v-btn variant="flat" class="text-button" @click.stop="$emit('update:modelValue', false)">{{ $t("menu.cancel") }}</v-btn>
+        <v-btn variant="flat" class="text-button" @click.stop="onOkButton">{{ $t("menu.ok") }}</v-btn>
+      </v-card-actions>
+    </v-card>
+  </v-dialog>
+</template>
+<script>
+export default {
+  name: "ConfirmationDialog",
+  props: ["modelValue"],
+  emits: ["update:modelValue", "ok"],
+  props: {
+    message: {
+      type: String,
+      default: "?",
+    },
+  },
+  methods: {
+    onOkButton() {
+      this.$emit("ok");
+      this.$emit("update:modelValue", false);
+    },
+  },
+};
+</script>