Commit summary length hints (warning at 50, error at 72)

[OchirErkhembayar]

This Pull Request fixes/closes #1635.

It changes the following:

• Added a warning_text to styles
• Updated warning for commit message to display yellow text at 50 glyphs and red text at 72 glyphs instead of just red at 50

I followed the checklist:

• [ ] I added unittests
• [x] I ran make check without errors
• [x] I tested the overall application
• [x] I added an appropriate item to the changelog

[pBouillon]

Not a maintainer but I would very much like to be able to override those values from a config file or equivalent

[extrawurst]

yeah this needs to be in the config