Library path fix

In this fix we use the full library path, determined during runtime using `__file__`, to open files such as `curves.ec`, `schema_sdb_v22.sql`, etc.

This is necessary because several files that get opened by tribler assume the working directory is the Tribler root. This does not work when executing on more exotic environments such as Android, where the working directory might be different.

Unfortunately this doesn't work when Tribler is packaged, i'd rather just pass the install_dir as we did with the termextraction.