Text Index. Issue with apostrophe and dash.

[aindlq]

Essentially the same as #1399 but for apostrophe:

SELECT * WHERE {
  ?text <http://qlever.cs.uni-freiburg.de/builtin-functions/contains-entity> ?subject;
    <http://qlever.cs.uni-freiburg.de/builtin-functions/contains-word> "Villa* D'Este*".
  ?subject a <http://www.cidoc-crm.org/cidoc-crm/E53_Place>
}

ERROR: Assertion `isValidVariableName(_name)` failed. "?ql_matchingword_text_d'este" is not a valid SPARQL variable. Please report this to the developers. In file "/qlever/src/parser/data/Variable.cpp " at line 18

[aindlq]

The same issue is with dash, so if contains word is bhex-le-2017-14-005* one gets the following error:

ERROR: Assertion `isValidVariableName(_name)` failed. "?ql_matchingword_text_bhex-le-2017-14-005" is not a valid SPARQL variable. Please report this to the developers. In file "/qlever/src/parser/data/Variable.cpp " at line 18