Merged export controller and services from rc2_dev branch

Also split the exportService into a metadata part and an export part.
However, no extra changes or improvements were made to make the export
work. Just the code is merged.
Merged frontend code for exporting from rc2_dev
Merging changes in dataExportService from rc2_dev to use core-api for
exporting
Merged even more export code from the rc2_dev branch to make exporting
work.
Removed references to the core-db, as well as unused imports
Remove 'created by ...' comment

We decided not to include those
Removed reference to core-db in export functionality.

This commit depends on changes in core-db (commit 930b474) and core-api
(commit 8906be9).
Reimplemented counting patients with clinical data
Adjusted export to also handle non BiomakerDataRow objects
Merge remote-tracking branch 'origin/master' into features/FT-835-merge-hd-export
Forgot to organize imports
Moved GenericJobService to src as it is not a service
Merge pull request #53 from thehyve/features/FT-835-merge-hd-export

Features/ft 835 merge hd export