Modify RecordCorruptedException class hierarchy

Modify RecordCorruptedException class hierarchy

So far there was only one type of record Cynara could read from its
database. If any corruption was detected, BucketRecordCorruptedException
was thrown.

Now database will contain information about not only buckets and
policies, but also some metadata for them (in this case - checksums).
Need for exception superclass for handling corrupted records emerged.

Patch modifies exception class hierarchy and adds new exception type:
ChecksumRecordCorruptedException.

Change-Id: I3af6bd20b57e17ec31d766f138595920c7a413bd