Plugin search - Diacritical marks, accents

Nobody has claimed this yet.

Make plugin search aware of [diacritical](https://en.wikipedia.org/wiki/Diacritical) marks, accents.

### Enhancement Summary
Make letters with diactitical marks turn up in search results sorted as if it was not having a diacritical mark, base letter. Possibly make this sorting optional (setting). In some languages diacritics affects sorting and then [in some others they don't.](https://portuguese.stackexchange.com/questions/5797/do-diacritical-marks-accents-affect-alphabetical-sorting-of-words). We would probably need to roll our own as **QString::localeAwareCompare()** may not work:
https://doc.qt.io/qt-5/qstring.html#localeAwareCompare-1
https://stackoverflow.com/questions/286921/efficiently-replace-all-accented-characters-in-a-string/9667817#9667817

#### Justification
Not many plugins use letters in the name other than the ones provided by the English language but when they do the result is quite confusing. The only example out there I've come across so far is Rézonateur by https://github.com/jpcima/rezonateur

In LV2 plugins there is support for localization of the name but in case this is not implemented or has been missed it would be good to catch the odd letters. In the case of the plugin above it will not turn up in a search for 'rezonateur' and if you scan the list of plugins it will also not turn up around re* but later. You may miss that the plugin installation succeeded.


Start by locating the plugin search and sorting entry points, then review QString::localeAwareCompare() and the linked Qt documentation to assess whether it meets the requested behavior. Check how LV2 plugin names are localized and how search results are ordered. Done means accented names such as Rézonateur are found by their base spelling and sorted consistently, with any setting behavior clearly defined.

Written by the indexing model from the issue text.