Enable del, delKind, purge within quota exceed

:Release Notes:
Allow to perform del, delKind, purge operations in condition of quota exceeded.

:Detailed Notes:
Fixed reported negative available quota to positive values only.
Reserved space for deleted flag for new records.
Fixed operations ordering for index update during record deletion.

:Testing Performed:
tested on local build

:QA Notes:
1. fill-in main db with test data using 'put' till get 'quota exceeded' report msg.
2. check quota status
3. delete some records
4. call 'purge' method
5. add one more record with 'put' --> ok
6. add some more records will cause 'quota exceeded'

:Issues Addressed:
[GF-59374] DB8 a problem of miscalculated Quota Size

Open-webOS-DCO-1.0-Signed-off-by: Igor Kuksyuk <igor.kuksiuk@lge.com>

(cherry picked from commit cfa440b6e1995eaf49f44ae65953dc862fff7ea0)

Change-Id: I31b211dadb7ee2133db61b369f8fef4f9d4b39e1
Reviewed-on: https://g2g.palm.com/4559
Reviewed-by: Oleksii Uratkin <oleksii.uratkin@lge.com>
Tested-by: Oleksii Uratkin <oleksii.uratkin@lge.com>