LDEV-4825 Fix general stats generationTake into account Scratchie (multiple learners answer the same asleader) and Assessment (answers are in a different table) specificstuff.
LDEV-4745 Remove all /r and /n from questions' title, description and optionsAlso perform this action for the initial insert of MCQ tool questionsinto tmp_question, as otherwise it will cause problems later whenprocessing Scratchie.
LDEV-4745 Trim new line characters during migrationBy default only spaces are trimmed. It leads to same questions being notmatched when they have different whitespace at the end.
LDEV-4746 Ignore CKEditor during validationThere is no rule for Scratchie description anyway. And validate plugintries to validate a CKEditor div with contenteditable="true" but with noid or name. There is no point in doing it as contents get moved to anamed textarea before submit.
