Add confirmation for ban/make admin etc

Also, fix Firefox problem with dialog jumping around.

src/components/Profile.vue

@@ -112,6 +112,7 @@
       v-model="showEditPasswordDialog"
       class="ma-0 pa-0"
       :width="$vuetify.display.smAndUp ? '940px' : '80%'"
+      scroll-strategy="none"
     >
       <v-card :disabled="settingPassword" class="dialog-content">
         <h2 class="dialog-title">{{ $matrix.currentUser.is_guest ? $t("profile.set_password") : $t("profile.change_password") }}</h2>
@@ -219,6 +220,7 @@
       persistent
       class="ma-0 pa-0"
       :width="$vuetify.display.smAndUp ? '688px' : '95%'"
+      scroll-strategy="none"
     >
       <div class="dialog-content text-center">
         <v-icon  size="30">notifications_active</v-icon>