Eliminate document properties from search results which are null or blank

**Is your feature request related to a problem? Please describe.**
I am playing around with Dejavu and many of my document properties are null or blank.

**Describe the solution you'd like**
When i click on the search button via the search preview I don't want the results to include properties from the doc where the properties are blank or null,

**Describe alternatives you've considered**
I haven't considered any alternative so far.

**Additional context**
Lets say i have a document like this
{"firstName":"Asfand", "lastName":"Hikmat","Location":"UK", "salary":null},
{"firstName":"Maria", "lastName":"ZaiZai", "location":"UK", "salary":"2000$"

When i search for this document in the search UI for UK can the result set include something like this.
"firstName":"Asfand", "lastName":"Hikmat","Location":"UK"
"firstName":"Maria", "lastName":"ZaiZai", "location":"UK", "salary":"2000$"

Note for the first doc since salary is null we don't show it in the search UI.

No files or tests are named. Start by reproducing the search-preview result with the example documents, then trace the JavaScript/React search-result rendering path. Done means the UI omits null or blank properties while retaining populated fields in matching documents.

Written by the indexing model from the issue text.