Add unit tests for arrays and "

OC_Util::sanitizeHTML() also supports array but we actually had no unit test for it. Additionally this commit introduces a test for escaping " into &quot;
Fix indentation
Remove uneeded newline
add setting to set default expire date
Merge pull request #8335 from owncloud/sharing_set_default_expire_date

[sharing] allow admin to set default expire date

* owncloud/sharing_set_default_expire_date:
  add setting to set default expire date
Merge pull request #8304 from owncloud/add-xss-tests

Add unit tests for arrays and quotationmark

* owncloud/add-xss-tests:
  Remove uneeded newline
  Fix indentation
  Add unit tests for arrays and "
add additional rows to the select statement, 'stime' is needed for the expire check
Merge pull request #8339 from owncloud/fix_unit_tests

fixing unit tests
Add flv to known mimetypes