Re-generate instant preview dashboards for a new or updated dashboard template

• Upon the startup of an Optimize instance, the backend shall check if a template has changed (e.g. by version) or if a new template has been added to Optimize. If that is the case, then the instant preview dashboards need to be re-generated.
• Existing preview dashboards should be deleted and new ones created instead
• The case in where Optimize is upgraded to the newer version (with instant preview dashboards) from an older one also needs to be considered. Meaning that Optimize will check if existing processes already have instant preview dashboards defined for them, and if not, new one(s) shall be generated

Testing notes

This shall be tested in conjunction with OPT-6670 and OPT-6671. So see testing notes for OPT-6671 for testing from a user's perspective.

Alternatively the endpoint that this ticket provides can also be tested on its own, to do that please do the following:

1. Open Optimize with Developer Tools open (F12)
2. Navigate to any old dashboard
3. Right click on the request that is made to the backend for the API call to retrieve the dashboard, and choose Copy -> Copy as cURL
4. Go to postman and import the copied request as Raw Text and save the request
5. Change your request URL from 

   https://<OPTIMIZE_URL>/api/dashboard/<DASHBOARD_ID>

   to

   https://<OPTIMIZE_URL>/api/dashboard/instant/<ANY_PROCESS_DEFINITION_KEY>

1. Run the request above. You should get a response with a newly created dashboard data
2. Copy the ID of the dashboard from that response
3. Open the following URL in your browser 

   http://<OPTIMIZE_URL>/#/dashboard/<THAT_DASHBOARD_ID>

    

1. Please note that it's normal if the reports are not being shown due to lack of authorization. This will be dealt with in a separate ticket