Redundant facet options on CCKP

[Bankso]

Noted in a comment to #99 by @aclayton555:

Investigate why we have some imaging assay types showing up multiple types in our facet options (note: not specific to imaging assay types, but worth tidying up in this process)

There are instances of resource 'Assay', 'Tissue', 'Tumor Type' facets showing the same filter multiple times. After some investigation, @vpchung and I noted that there seems to be some extra whitespace included in annotations where this occurs, e.g., Imaging Mass Cytometry vs Imaging Mass Cytometry

Suggested solution:
Add additional functionality to our database management scripts that removes leading/trailing whitespace in columns that serve as a source of CCKP facets