Head truncation drawing is incorrect

[chansen22]

Describe the bug
Setting lineBreakMode to .byTruncatingHead or .byTruncatingMiddle causes the label to paint incorrectly. It truncates the head and the tail, or the middle and the tail, and it doesn't paint the correct section of the label (for .byTruncatingHead).

To Reproduce
Steps to reproduce the behavior:

1. Run example app
2. See truncated head and truncated middle examples

Expected behavior
It should paint like UILabel paints. Something like the last line of the string, with the truncation token only appearing at the front of the label, instead of at the front and the end.

Screenshots

Additional context
Potentially changing the truncation code to check against lineBreakMode before deciding how to truncate might be the fix.