[Research] /legal/search endpoint: Fix exact string match to only return exact strings from documents

[patphongs]

What we’re after

exact string match to NOT include stem words, but include common words like “to”, “not”, etc.
We should do more research to see if we can not include stem words and search stop words (if needed) only for exact string match

Currently the stop words functionality seems to be working as expected ie "reason to believe". Is searching for just a stop word ie "NOT" necessary functionality

Related ticket(s)

(Include the tickets that either came before, after, or are happening in tandem with this new ticket)

• [Research] /legal/search endpoint: Respondents need capability for exact string match #5830

Action item(s)

(These are the smaller tasks that should happen in order to complete this work)

• research not searching stem words
• research searching stop words

Completion criteria

(What does the end state look like - as long as this task(s) is done, this work is complete)

• We have a plan in place for exact string match changes if needed and ticket for implementation is created

[cnlucas]

We are going to receive more specific examples for this---"reason to believe" is working for us.
We should do more research to see if we can not include stem words and search stop words (if needed) only for exact string match