Prevent line breaks in draggable (first) table cells

Problem/Motivation

Right now, every element in a draggable table's first cell (this is where the drag-handle and the indentation are added) are floated to right (or to left for RTL languages). This makes the hierarchy of the taxonomy terms hard to follow, and besides that it is almost impossible to change the level of those taxonomy terms thats drag-handle is rendered on the left (RTL: right) side of the table cell (because of the high number of the preceding indentation elements).

Screenshots about the current output:

Steps to reproduce

1. Install Drupal with the Standard profile
2. Add about 10 taxonomy term to the 'Tags' vocabulary.
3. Adjust the same taxonomy term hierarchy as on the attached screenshots.
4. Check the overview page of the 'Tags' vocabulary with a smaller browser window width.

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet