Install SQLite on the OpenConext phpfpm container

[MKodde]

Sqlite is required to run certain db integration tests. Having a MySQL database in a test env often proves to be overkill so we opted for a lightweight SQLite solution in the User Lifecycle project. The SQLite PHP extension was already compiled into the Alpine PHP image. But SQLite itself had to be installed

[quartje]

Where is the test located that uses this? If it uses Docker, a Docker mySQL image should be trivial to use, which also creates a situation that looks more like what is used on production