[re #12469] Repair bug of github pump not pumping all Commits
- changed database schema work_item and work_item_change to handle 4 bytes emojis setted utf8mb4
- changed database schema work_item to handle longer urls changed varchar size from 256 to 1000
- disabled logic for handling not saving Branch duplicitly (hardly can be donned - Branch is not dirrectly connected to project or doesnt have any unique property)
- repair saving Commit if user is null
- skipping not saving filechanges of subgit module
- repair invalid mapping title of commit to work_item