feat: add workoutbrandname to metadata

[ArekChr]

Description

Added support for optional workoutBrandName metadata in workout saving functionality.

Type of change

• [x] New feature (non-breaking change which adds functionality)

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have made corresponding changes to the documentation
• [x] I have checked my code and corrected any misspellings