[SUGGESTION] Input of MEX files from non-cellranger formats

[cflerin]

Is your feature request related to a problem? Please describe.
I want to use MEX input from STAR solo. For example:

sample_id.Solo.out/Gene/filtered/
├── barcodes.tsv
├── features.tsv
└── matrix.mtx

Describe the solution you'd like
Add capability to take this input data to getDataChannel / file_converter.

Describe alternatives you've considered
I can create a directory of symlinks in the cellranger format. But in this case, I need to gzip the files so it requires a copy of the data to be made anyway. None of the scanpy/anndata solutions work for this either. They assume cellranger structure, or will only load the matrix without barcodes and features annotation (in the case of read_mtx).

Additional context
Add any other context or screenshots about the feature request here.