rework display of bandmap entry for QTC

- respect column width for bandmap display. Leave at least on space
  between columns. Truncate long entries and show '..' to indicate
  truncation (e.g. CT1/DL1JBE/p will become CT1/DL1JB..)
- show max. 11 chars from call if no QTC
- shows max 9 chars from call plus QTC number if QTC
- drop unneeded checks