[Spike] Figure out the ways to improve the current plugin export pipeline

Currently we are at the stage where it's getting harder to improve or modify export of advanced designs, their components and properties.

Reorganization, streamlining and removal of code duplication is a must.

Currently we organize supported Figma types somewhat well, but lack at organization of exported metadata/qt types.

Properties export is chaotic. Export of custom user-assigned properties is misaligned between different Figma types

Export fallback options for metadata/qt types are heavily misaligned.

Instances export is behind of what QDS Bridge can do.