wcst_import fails to import files in subdirectories

[Dimitar Misev]

Files listed with relative path in the same directory as the ingredients file can be imported fine, e.g.

"paths": [ "20200101.tif" ]
...
Collected first 1 files: ['/data/tiffs/20200101.tif']...

However, if the file is in a subdir it will not be resolved to an absolute path and the import fails:

"paths": [ "tmp/20200101.tif" ]
...
Collected first 1 files: ['tmp/20200101.tif']...