ConceptNot ExistException should be validated (user-readable message)

[DKashenko]

Expected behavior

Some warning message is shown. After making some validation in webApi, we should add some message on frontend side.

Actual behavior

Nothing happened. Error from the backend
WebAPI/estimation/54/generation/data_source
Request Method: POST
Status Code: 500
{"payload":{"cause":null,"stackTrace":[],"message":"An exception occurred: java.lang.reflect.UndeclaredThrowableException","localizedMessage":"An exception occurred: java.lang.reflect.UndeclaredThrowableException","suppressed":[]},"headers":{"id":"e96589e0-a703-c453-a26a-1274aa50f422","timestamp":1623400492299}}

Steps to reproduce behavior

1. Open Atlas
2. Estimation -> Run analysis on DS (The Data source should not contain the concepts )