fix: dashboard cache (sequence of actions)

[weisdd]

Description

With url-based dashboards, a few status fields are supposed to be used for caching. It doesn't happen though, because the r.refreshDashboard() call (fetches the latest version of CR) is made right after the r.Dashboard.Status is prepared, effectively dropping all cache data.

This PR restores correct sequence of actions.

Relevant issues/tickets

Fixes: #832

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• This change requires a documentation update
• I have added tests that prove my fix is effective or that my feature works
• I have added a test case that will be used to verify my changes
• Verified independently on a cluster by reviewer

Verification steps

1. Deploy something like:

apiVersion: integreatly.org/v1alpha1
kind: GrafanaDashboard
metadata:
  name: grafana-dashboard-from-url
  labels:
    app.kubernetes.io/instance: grafana-operator
spec:
  url: https://grafana.com/api/dashboards/11176/revisions/1/download

2. Cache data in CR status fields should get populated.

[HubertStefanski]

LGTM