New feature - Upload file with new events

[JaimeLeon2]

The bulk upload process although functional, it requires human intervention by the system administrator, which sometimes can take weeks, depending on time availability.
Why not provide an upload button in Hubhop that will take a text file in a specific format, like say CSV, or xml, containing new event information.
The file processor would:

1. Check file syntax compliance.
2. Check event name rules are complied (no special character, no leading nor trailing blanks)
3. Check each new aircraft+event name is non existing.
4. Check category label compliance. No new categories are allowed.
5. If no errors are detected, add file contents to the database.
6. If any issue is detected, reject entire operation and issue an error message indicating what the non-compliance was and the offending line number.