Reconcile unicode characters in record attributes/searchable terms

[jsstevenson]

We handle non-ASCII characters in database records by converting them to HTML escape sequences:

(however github's markdown renderer will display them as unicode -- the actual text of the value below is & folloewd by alpha followed by ;)

"label": "CXCL12α",

http://normalize.cancervariants.org/therapy/normalize?q=pubchem.substance:135651881

However, these values aren't properly handled either in the SwaggerUI interface (the label value above is converted to CXCL12&alpha) or via an HTTP request (the label value above gets the escape sequence cut entirely and the final query is CXCL12 which is an entirely different drug)

[korikuzma]

• html.unescape --> urrlib.parse.unquote in main.py

[mcannon068nw]

From recent analysis of concept mismatches, some concepts' child terms are failing to normalize to anything. Not all, but a number of these seem possibly due to special characters.
concept-mismatches-nan-ddb20220915.xlsx