HPO name search breaks with colon in string

[stolpeo]

Describe the bug
The name search returns a 500 error when the string contains a :. It seems to interpret the first part of the string up to the : as a field.

## Input: "HP:"
curl 'http://localhost:8000/proxy/varfish/viguno/hpo/terms?name=HP%3A'
Error parsing query: Syntax Error: HP: 

## Input: "HP:00"
curl 'http://localhost:8000/proxy/varfish/viguno/hpo/terms?name=HP%3A00'
Error parsing query: Field does not exist: 'HP'

[stolpeo]

Actually I don't know if it is intended to also search by term id, but the error is strange anyway.

[holtgrewe]

The full-text search engine interprets this in the query. Will be fixed in #173.