"Samples" and "current_samples" can't be used by concurrent users

[SamuelNicaise]

When multiple users use the same database concurrently on a shared network drive:

Issue with "samples" source:

• user A selects samples with the sample modules
• when user B selects samples --> selected variant lists is changed for user A without obvious visual cues except total number of variants

Same issue with "current_samples" source:

• user A double clicks on a sample, a genotype columns appears and "current_samples" is changed
• when user B double clicks on a sample: for user A, the genotype column stays the same but variant selection changed, without obvious visual cues except total number of variants

Currently, we deal with the issue by recommanding users to use manually created sources instead of those features.