Returns true if intervals are normalized. Normalized intervals
satisfy these criteria:
1. All intervals must be non-empty.
2. Intervals must be sorted by tag.
3. Intervals with the same tag must be sorted by coordinates and
must not overlap.
structRegion(Number, Tag, string tagAlias = null, Tag emptyTag = Tag.init)
Returns true if intervals are normalized. Normalized intervals satisfy these criteria:
1. All intervals must be non-empty. 2. Intervals must be sorted by tag. 3. Intervals with the same tag must be sorted by coordinates and must not overlap.