[BUG] /training/analytics/overview fix

[ffrose]

Bug description:
As of right now, when deployed model does not have cross-validation done, it does not load the page:

Deployed model with existing cross validation:

Expected behavior:
When model has empty object for cross validation report, then add fallback in GUI: "This model does not have cross validation report/Sellel mudelil puudub ülevaade."

Screenshots:

Additional information:

[ExiRain]

#1059 Added safety for report, if none present we will have a message to say that