PIM-3434: throw exception when media file does not exist

| Q                    | A
| -------------------- | ---
| Bug fix?             | Y
| New feature?         | N
| BC breaks?           | N
| CI currently passes? | Y
| Tests pass?          | Y
| Scenarios pass?      | Y
| Checkstyle issues?*  | N 
| PMD issues?**        | N
| Changelog updated?   | Y
| Fixed tickets        | -
| Doc PR               | -
normally yes
but this method is public, not the other one
and it's good what can be thrown for the public api even if it's come from an inner method