Context

Right now, there is a list of songs on this sub-page: http://localhost:3000/songs It's also reachable by clicking on "Lieder" in the navigation, then "Alle Lieder". This list will quickly get confusing because our choir has a lot of songs! Therefore it will be helpful to have a way to filter the list to only show songs with certain values for certain fields.

Acceptance criteria

• The song list is filterable by the following fields:

• language
• is repertoire
• genre
• register
• time signature
• arranger

• The filters are shown as select boxes above the song list and there is a button to apply the filters (reloading the page with query parameters set according to what filters are selected)
• All values currently in the database for these fields should be selectable to filter by (plus a "no filter" placeholder). For example if there are songs with the languages "English" and "German" in the database, the language filter select box will have these values to choose from: "no filter" (blank), "English", "German"