DS-2333 fix OOM error on large image files

https://jira.duraspace.org/browse/DS-2333

Seems there are more diffs now than earlier, sorry ... I have been working with 4.1 all along

My code changes are only around 'catch (OutOfMemoryError oome) ... return false ...
I think your changes need to not erase as many existing things. Likely the result of your code being based off of a slightly older version of DSpace. The goal is to have as small of a diff as neccessary. i.e. just the things relevant to the oom.