Fix fill in the blanks issues

[maciejhubert]

There are 2 issues with Fill in the blanks question type. The first one is the text not aligned vertiacaly:

The second one is unnatural blinking of the dragged element.

Nagranie.z.ekranu.2026-02-9.o.16.58.47.mov

The blank spaces should always be of the same size, to avoid it (probably the longest filler word for that exercise should be considered).

[maciejhubert]

There still is an issue, drag&drop should not affect the sentences anyhow:

Nagranie.z.ekranu.2026-02-18.o.08.56.31.mov

Also this frame looks weird after dropping the sentence: