When entering "Alasehir", items with the label "Alaşehir" should be found, without an aliases being explicitly defined. Similarly, "Munchen" should find "München". This should work at least for roman-based diacritics. Not sure if such "simplification" is applicable for other scripts.

Implementation notes:

• a rough-and-dirty implementation can be based on converting to DNF, and then stripping all non-ascii characters. This will turn Ä into A, and so fort. It will however break non-roman scripts completely, so we need a whitelist of language codes (or character ranges).
• Perhaps Elastic/Lucene already provides this, so we'd get it for free with Cirrus integration.
• If we want to implement this without Currus/Elastic/Lucene, it should go into TermSqlIndex::getSearchKey()