add unsubscribe from all button to inbox

app/routes/threads.py

@@ -1,6 +1,7 @@
 from flask import Blueprint, redirect, url_for, render_template, request, abort
 from functools import wraps
 from ..auth import login_required, get_active_user, is_logged_in
+from ..db import db
 from ..models import Threads, Posts, Topics, Users, Reactions, Subscriptions
 from ..util import get_form_checkbox, time_now
 import math
@@ -170,6 +171,14 @@ def unsubscribe(thread_id):
 @login_required
 def unsubscribe_all():
     user = get_active_user()
+    subs = Subscriptions.findall({'user_id': user.id})
+    if not subs:
+        return redirect(url_for('users.inbox', username=user.username))
+    with db.transaction():
+        for sub in subs:
+            sub.delete()
+
+    return redirect(url_for('users.inbox', username=user.username))
 
 @bp.post('/subscriptions/mark-read/')
 @login_required