Idea to resolve LV2 reloading problem

[jpcima]

We know that LV2 has problem reloading the SFZ files sometimes, because of the State path system which keeps a symlink, and also does not permit portable sessions.

The idea of a workaround is as follows:

• store in the state blob an additional String value, which is the unmodified raw path to SFZ file
• on loading, check if the symlink file is present and resolves to an existing file. OK => use that
• not OK => use the "unmodified raw path" to perform VST-style fuzzy search in the user dirs. Load the file that results from that

Also

• enable the user-path editing in the LV2 UI
• replicated SfizzFileScan logic into LV2 code

tag @unfa