IDLE: Select current line when text is not selected while doing copy

Feature or enhancement

When the selection is empty, select and copy/cut the current line.

Original Python’s IDLE can copy empty text, but it seem make no sense.

Previous discussion

Discuss at: https://discuss.python.org/t/i-made-some-improvement-for-idle-can-i-contribute-to-idlelib-library-in-python-project

Usage: https://github.com/znsoooo/IDLE-Advance

Implementation: https://github.com/znsoooo/IDLE-Advance/blob/master/idlealib/CopyNoSelect.py

Linked PRs

• gh-126034
• gh-145134