Flipnic file tools 2.1 (Pre-Release 1)

This pre-release provides some functionality that is missing from the latest stable release, such as (somewhat) accurate HD/BD to SF2 conversion and pretty borked LP4 model preview.

Supported operating systems:

• Windows (ARM64/x86_64)
• macOS (Apple Silicon)
• Linux (x86_64)
• Linux (ARM64/CLI only)

Full Changelog: 2.0...2.1-prerelease