(fix:#227) Apply Theme Selection Color

[thecoolwinter]

Description

Fixes some theme colors not applying when the editor is first opened.

Moved configuration to 3 methods, one for the textview, gutter, and scroll view respectively. These functions are used in both the reloadUI and loadView methods to ensure it's consistent in both initial loads and reloading.

Related Issues

• closes #227

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

Screenshots

https://github.com/CodeEditApp/CodeEditSourceEditor/assets/35942988/71ea08df-c44c-425f-8cdb-280fd693f56b