New: drawCenteredText in NanoVGHelper

[ghost]

Description

Checklist

• [x] I made a clear description of what was changed
• [x] I stated why these changes were necessary
• [x] I updated documentation or said what needs to be updated
• [x] I made sure these changes are backwards compatible
• [x] This pull request is for one feature/bug fix

[TheKodeToad]

You realise you could've pushed to the previous PR, right? xD

[ghost]

username :(