Grav modular page success message never resets

```yaml
---
...
form:
name: contact-form
action: /home
...
process:
- reset: true
- message: "Thank you!"
...
---
```

@rhukster This shows a success message once submit button is clicked. The success message stays on the page even if the cache is reset shift+cmd+R. This looks like an odd behaviour.

Removing the cookies from the page will show:

> OOPS THERE WAS A PROBLEM, PLEASE CHECK YOUR INPUT AND SUBMIT THE FORM AGAIN.

Is there a particular reason to have the notifications not reset on the form submission even with the `reset: true` flag?

Reproduce the issue with the YAML form configuration shown, including `process: reset: true` and the success message. Check what happens after submission, a cache reset with Shift+Cmd+R, and cookie removal. Done means the notification behavior is explained and the form reset state is consistent after submission and cache refresh.

Written by the indexing model from the issue text.