Support meaningful error messages (Kibana)

[eladiw]

Context:
Sometimes the search fails, whether due to a bug or a bad input from the user, e.g. when searching for an invalid field

NotARealColumn:something

The error Kibana displays is "Internal server error".

This issue suggest:
a. provide a more meaningful error
b. if possible wrap with user friendly error msg -> "invalid column try again"