<!--- Verify first that your feature was not already discussed on GitHub -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
<!--- Describe the new feature/improvement briefly below -->
Atm, there is no way to put the server in rescue mode

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
hcloud_server

##### ADDITIONAL INFORMATION
<!--- Describe how the feature would be used, why it is needed and what it would solve -->
Atm, Since I can use the hetzner api, I'm using the following code to put it into rescue:
<!--- Paste example playbooks or commands between quotes below -->
```yaml
    - name: Enable rescue
      uri:
        url: "https://api.hetzner.cloud/v1/servers/{{ item }}/actions/enable_rescue"
        method: POST
        status_code: 201
        body_format: json
        body:
          type: "linux64"
          ssh_keys: [341997]
        headers:
          Content-Type: "application/json"
          Authorization: "Bearer {{ hostvars['localhost']['hetzner_api_token'] }}"
      with_items:
        - "{{ server_id }}"
```

<!--- HINT: You can also paste gist.github.com links for larger files -->

if previous_server_status == Server.STATUS_RUNNING:
                if not self.module.check_mode:
                    if self.module.params.get("force_upgrade") or state == "stopped":
                        self.stop_server()  
                    else:
                        self.module.warn(
                            "You can not upgrade a running instance %s. You need to stop the instance or use force_upgrade=yes."
                            % self.hcloud_server.name
                        )
            timeout = 100
            if self.module.params.get("upgrade_disk"):
                timeout = (
                    1000
                )  
            if not self.module.check_mode:
                self.hcloud_server.change_type(
                    server_type=self.client.server_types.get_by_name(server_type),
                    upgrade_disk=self.module.params.get("upgrade_disk"),
                ).wait_until_finished(timeout)
                if state == "present" and previous_server_status == Server.STATUS_RUNNING or state == "started":
                    self.start_server()
            self._mark_as_changed()
        self._get_server()
    def start_server(self):
        if self.hcloud_server.status != Server.STATUS_RUNNING:
            if not self.module.check_mode:
                self.client.servers.power_on(self.hcloud_server).wait_until_finished()
            self._mark_as_changed()
        self._get_server()
    def stop_server(self):