refactor: improve YAxisRenderer.renderAxisLabels

[t49tran]

PR Checklist:

• I have tested this extensively and it does not break any existing behavior.
• I have added/updated examples and tests for any new behavior.
• If this is a significant change, an issue has already been created where the problem / solution was discussed: [N/A, or add link to issue here]
  

PR Description

Small refactor to YAxisRenderer by replacing the nested if / else with two functions to calculate the label position x and label text alignment.

Hopefully, this is helpful and improve readability a little bit.