Log full AWS exceptions

[glebshalyganov]

Duplicate of: jmix-projects/jmix-awsfs#5

Environment

• Platform version: 7.2.x
• Addon version: 1.0.1

Description of the bug or enhancement

When catching exceptions in saveStream/openStream methods, log the initial exception before throwing FileStorageException.
E.g. log.error("Error saving file to AWS", e)
Otherwise the useful information about the error (like "access denied") is lost.