Don't Try to Set a Negative Frame Height

[thecoolwinter]

Description

Fixes a potential recursion where CETV tries to set it's frame to a negative number (due to overscroll & scroll inset weirdness). This adds a super simple sanity check to make sure we limit the textview to a 0 frame at minimum.

This hang would occur when no content is present, making the content size an odd number, which also makes scroll views freak out on macOS.

Related Issues

• 🐞 Editor Hangs When 'New File' Button is Used CodeEdit#2049

Checklist

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

Screenshots

N/A, fixes a hang.