OO-291: first step: move business gourp manager to a business group service, remove dependency to the context...

OO-213: make OpenOLAT more robust against corrupted course, mark them in details view, make home resistant to corrupted courses, give the possibility to delete them

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branch : i18n_OO

FXOLAT-437:  don't delete efficiency statements of existent course, delete all UserCourseInfos before deleting the repository entry

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branch : i18n_OO

OO-170: refactoring of the property table, move efficiency statements and initial/recent launch dates to their own table

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branch : 80-patch

FXOLAT-424: reduce the number of output in log files from the UserActivityLogging (especially in QTI and EffiencyStatment)

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branch : i18n_OO

OO-15: set last update and initial launch date invisible as default, add table configuration for Node > User in Assessment Tools

OO-35: load only once the olat.properties and olat.local.properties and optimize the search of spring configuration

FXOLAT-296	: enhanced REST API for notifications (by type), better unit tests this function, optimize the way to get notifications by type in the controller