Issue when filtering by title

[agbeltran]

Description:
When navigating experiments and then filtering by title, I seemed to have found a bug.

To reproduce:

• in DG for ISIS, browse by Experiments
• choose the GEM instrument
• in the title filter, enter 'tests'

URL: https://data.isis.stfc.ac.uk/browseStudyHierarchy/instrument/28/study?filters=%7B%22studyInvestigations.investigation.title%22%3A%7B%22value%22%3A%22tests%22%2C%22type%22%3A%22include%22%7D%7D&sort=%7B%22studyInvestigations.investigation.startDate%22%3A%22desc%22%7D

the first 3 results seem OK, but not sure why the fourth result is listed - see screenshot

Now, changing the filter from include to exclude, note that the first result contains 'tests' (and it wasn't given in the previous list)

URL: https://data.isis.stfc.ac.uk/browseStudyHierarchy/instrument/28/study?filters=%7B%22studyInvestigations.investigation.title%22%3A%7B%22value%22%3A%22tests%22%2C%22type%22%3A%22exclude%22%7D%7D&sort=%7B%22studyInvestigations.investigation.startDate%22%3A%22desc%22%7D

Could there be hidding characters that are affecting these filtering results?

Acceptance criteria:

• Investigate and fix filtering issue

[louise-davies]

@agbeltran we think this may be related to #1390 - which is a problem with the current implementation of the study view