Update samplesInContext utility method to handle bare sample IDs

The new format for the sample filter in context is to just use the
sample ID and not the label and ID in the form {label: label, value:
id}. Because of this, the utility method needs to account for the raw ID
and lookup the label from the sample list as a whole rather than pulling
the label from the context itself.

Signed-off-by: Don Naegely <naegelyd@gmail.com>
Merge pull request #381 from cbmi/issue-380

Update samplesInContext utility method to handle bare sample IDs