Improvment - Verify tables exists

[eladiw]

IMO when a user creates a new dashboard the process is very smooth. However,
after you supply credentials (e.g. AppInsights cred) you don't know if the tables existing in AI will be suitable to the dashboard you requested. if they are not => broken dashboard.

I suggest a 'pre configure' step to query AI and verify all tables exists, then you can cancel the dashboard creation or at least alert its not compatible.
from there you can add more improvements such as a link to what needs to be done to make it compatible.

[morsh]

@Ilanak - can this be done using the AIA API?