feat: add password reset for usermanager (#2688)

* feat: add password reset for usermanager
- add a reset_key to account table
- add ?reset_key= GET arguments to index.html and show reset form if provided
- superuser can generate and copy reset url with key to share
future ideas:
- could add send forgot password email if user fill out email address
* feat: simplify reset key
* test: use reset key
* test: add more tests
* test: reset passwords do not match
* test: `reset_password_auth_threshold_expired`

---------

Co-authored-by: Vlad Stan <stan.v.vlad@gmail.com>

lnbits/static/js/base.js

@@ -81,6 +81,17 @@ window.LNbits = {
         }
       })
     },
+    reset: function (reset_key, password, password_repeat) {
+      return axios({
+        method: 'PUT',
+        url: '/api/v1/auth/reset',
+        data: {
+          reset_key,
+          password,
+          password_repeat
+        }
+      })
+    },
     login: function (username, password) {
       return axios({
         method: 'POST',