CL-220,OO-613: update search in repository tab to the new method, fix double optimization to retrieve the access control objects, fix the user name cache to prevent always searching non-existing usernames, fix RS in assessment tool caused by FULLY_PASSED property for Onyx

OO-622,CL-225: remove username from GUI in place where is not really needed and students can see it. Mark others place with //TODO username where it need more works and/or the username is only visible by author/coach/admin... Additional fix the setup sql for MySQL (index too long).

OO-586: import members by user names, emails and institutional numbers, remove select box, update wording

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branch : 80-patch

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branch : bps