Case Insensitive Search

[Maartenvm]

Currently http://localhost:8080/overview?searching=fiets and http://localhost:8080/overview?searching=Fiets yield different results. This is because these words are listed as seperate paradigms in the database.
This should be changed in a future version. All case variants of the words should be considered when searching for a wordform (aka the search should be case-insensitive).
This has an impact on many aspects of the code, in both database, backend(API) and in the frontend. Multiple paradigms could be returned instead of one, transforming the schema needed by the charts.