tinyusb/msc_fat_view: Use link_tables for root entries

[kasjer]

This change extract several FAT root entries definitions to separate files so it's easier to see how to make custom entries.

This feature utilized newt tool features:

• link time tables (used for root dir entries)
• pkg.whole_archive switch that forces to search whole archive
• pkg.source_files (now package files are selected separately)