Avoid slow calls when updating StepsTranslator cache

unfilteredDomOffset is extremely slow under certain conditions, greatly limiting the iteration speed. This patch eliminates all calls that would trigger this slow call, improving iteration performance.

# Benchmark Results
## 100pages.odt
| Action | Master (e102327e) | PR |
|---------|-------------------------|------|
| Move to document end (ctrl+end)|586ms|484ms|
|Insert the letter 'A' (x100)|1236ms|1030ms|
|Align the current selection 'justify'|1934ms|1793ms|

## 1000pages.odt
| Action | Master (e102327e) | PR |
|---------|-------------------------|------|
| Move to document end (ctrl+end)|9626ms|7017ms|
|Insert the letter 'A' (x100)|4020ms|3306ms|
|Align the current selection 'justify'|33219ms|18329ms|