Navigate to next gapped or ungapped position in cursor mode

Navigating to the next gapped or non-gapped position is really useful for very large alignments or alignments involving very long sequences.

Many text editors provide a similar feature for jumping to the next word boundary. e.g. In cursor mode (F2), pressing SHIFT+<Arrow Key> should jump to the next 'word boundary' in the given direction (up/down a column or along a sequence to the next indel).