search for conditions returns 'bad request'

[areisle]

Describe the bug
when you search for a condition on the new statement page, if you type less than 3 characters it sends a search with keyword = '' which the api then returns as a bad request

To Reproduce

Steps to reproduce the behaviour:

1. go to /new/statment
2. type a character in the 'conditions' field
3. See error in console
   

Expected behaviour
it should not make a search request a all if the user hasn't typed 3 or more characters
and should have some message visible to the user that this is a requirement to see results

Versions (please complete the following information):
tested on dev deployment https://graphkbdev.bcgsc.ca/query-advanced in chrome

Version: dev (f72972b)