Previously we had two different defaults for the edition setting:
* one default was set to CEE but was only applied if the datasource
  settings page was opened and was only applied to the backend after
  "save" was pressed.
* the other default setting was set to RAW and was applied in the
  backend

If you use a provisioned datasource and did not specify the edition
explicitly, you saw "CEE" chosen in the UI, but the backend actually
used the "RAW" edition.

In order to align this, we chose to set both defaults to CEE.

**If you use checkmk raw edition and a provisioned datasource or created
the datasource with an very old version of this plugin** you have to take
manual action:
* if you use a provisioned datasource: specify the edition explicitly
* if you used a old version of this plugin to create the datasource:
  open the datasource settings, make sure the RAW edition is chosen, and
  save the settings.

You can use the following python script to check if you are affected:
(You can only be affected if you use the plugin to fetch matrices from
checkmk raw edition.)

```
import requests

GRAFANA_URL = "http://127.0.0.1:3000/"  # with closing slash

URL = f"{GRAFANA_URL}api/datasources"

GRAFANA_USER = "admin"
GRAFANA_PASSWORD = "password"
data_sources = requests.get(URL, auth=(GRAFANA_USER, GRAFANA_PASSWORD))

for data_source in data_sources.json():
    if data_source["type"] in {"tribe-29-checkmk-datasource", "checkmk-cloud-datasource"}:
        json_data = data_source["jsonData"]
        if "edition" not in json_data:
            print("found affected data_source:")
            print(f'  name: {data_source["name"]}')
            print(f'  id: {data_source["id"]}')
            print(f'  uid: {data_source["uid"]}')
```

We assumed that this can only happen if you query a Checkmk version that
has no graph query endpoints at all. But the enterprise REST-API
endpoint will return a 404 error in Checkmk raw edition, so we adapted
the hint for the user.

Unrelated fix: Checkmk should start with capital letter.