feat(ui): Dynamic stylesheets

[TheiLLeniumStudios]

Describe Pull request Allows anyone to contribute modified CSS files by placing them under html/styles/ folder. The styles can then be changed using Config.Style field

If your PR is to fix an issue mention that issue here

Questions (please complete the following information):

• Have you personally loaded this code into an updated qbcore project and checked all it's functionality? [yes/no] (Be honest) yes
• Does your code fit the style guidelines? [yes/no] yes
• Does your PR fit the contribution guidelines? [yes/no] yes

[BerkieBb]

Meant to request changes

[TheiLLeniumStudios]

@BerkieBb fixed all of the requested changes