[CAL-2965] Remove No users found error

[Udit-takkar]

Is your proposal related to a problem?

To the end user this error doesn't really tell much about what's wrong and why user is not found.

https://threads.com/thread/34561253728/34561258175?s=cetaiy3DJ4ESFWeh9D7Vjq

Describe the solution you'd like

Investigate further when this error occurs and display better error message like "time slot conflicting with calendar event"

_{From SyncLinear.com | CAL-2965}

[keithwillcode]

I was looking through this code the other day, we should be able to return the list of conflicts. This will be more useful than just a message saying there are conflicts.