Add bulk annotation helper on sample

[gregorjerse]

No description provided.

[dblenkus]

👌🏼

[mzganec]

Works well.

Feature request:

• Consider implementing also Sample.get_annotations, which would return all annotated fields in a dict. This type of output is more useful to bioinformaticians than the list of key-value pairs that we get from Sample.annotations.all().

Bugs:

• Both Sample.annotations.count() and Sample.annotations.all().count() return a wrong number of items. I annotated four fields and count() returned one.
• s.set_annotation (note the singular form) fails if the value is set to None, i.e., deleting a field is not supported.

[gregorjerse]

1. Helper get_annotations is implemented.
2. Bugs should be fixed now.

[mzganec]

Well done! Works as expected.

I noticed that set_annotation (note the singular form) requires explicit confirmation when deleting a field. That's fine, but note that bioinformaticians typically annotate all samples in a collection, so this may require them to press "y" several hundred times. A force argument would be nice to control the confirmation prompt. This issue doesn't need to be addressed immediately because set_annotations doesn't prompt for confirmation, so we can use that instead.

[mzganec]

Typo: annotation