Check to ensure samples that get a SequencingProcess._generate_sample_proj_value of None are NOT experimental?

[AmandaBirmingham]

Before a recent refactor, SequencingProcess._generate_sample_proj_value included the following TODO:

https://github.com/jdereus/labman/blob/f930206122f5adc0f12afb004021ce8fec77851e/labcontrol/db/process.py#L3215-L3221

Memorializing this here so it isn't forgotten. I vaguely recall we actually HAVE seen cases where the sample project was none for experimental samples, I think because they didn't have data in qiita.