Feat: add multi-type support for emby library stats

[Canti23]

Description

Enhances the Emby component to support multiple library types while maintaining full backward compatibility with existing configurations.

Examples

Single type (existing): "music" → "100 songs, 20 albums"

Multiple types (new): "music|movies" → "100 songs, 20 albums; 50 movies"

#681

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactoring

Checklist:

• I've read & comply with the contributing guidelines
• I have tested my code for new features & regressions on both mobile & desktop devices, using the latest version of major browsers.
• I have made corresponding changes to the documentation (README.md).
• I've checked my modifications for any breaking changes, especially in the config.yml file