Convert two commonly instantiated utils classes into static singletons

These two classes account for a measurable impact on performance. Turning them into static singletons saves on garbage cleanup and creation time.

| Action | master(21c3bc1ace6eb5b97d932d147dc572c7ec399134) | pr |
|----------|----------|--------|
|18. Align the current selection 'justify'|864ms|661ms|
|19. Remove the current selection|9799ms|9291ms|