Update Gutter Drawing Code

[thecoolwinter]

Description

Updates gutter line number drawing to use the same settings as CETV in this PR.

Related Issues

N/A

Checklist

• [x] I read and understood the contributing guide as well as the code of conduct
• [x] The issues this PR addresses are related to each other
• [x] My changes generate no new warnings
• [x] My code builds and runs on my machine
• [x] My changes are all related to the related issue above
• [x] I documented my code

[thecoolwinter]

Once #237 is merged the failing tests should be fixed.