Util.py exists to hold toplevel data and functions used in multiple modules.
These three are used in pyshell, test_sidebar, and elsewhere:
run.fix_scaling (also used in filelist);
editor.fixwordbreaks (rename to fix_word_breaks, also in filelist);
pyshell.fix_x11_paste (also in test_editmenu).
This will slightly simplify the idlelib import graph by breaking some loops.

**No previous discussion: Minor refactor.

Linked PRs

• gh-152728: IDLE - move 3 toplevel fix_xyz functions to idlelb.util #152729
• [3.15] gh-152728: IDLE - move 3 toplevel fix_xyz functions to idlelb.util (GH-152729) #152730
• [3.14] gh-152728: IDLE - move 3 toplevel fix_xyz functions to idlelb.util (GH-152729) #152731
• [3.13] gh-152728: IDLE - move 3 toplevel fix_xyz functions to idlelb.util (GH-152729) #152732