Make cassandra_static build using position independent code

[meghprkh]

This should help other toolchains.

If needed this can be gated behind a config flag.

For context, there are a few workflows where we want to produce a shared lib from a static archive, but do not want to rely on any other shared object being distributed. This is particularly common in the shared object extension world. For example I want to distribute duckdb_cassandra.duckdb_extension.so without any external dependencies. I would like to link in the cassandra driver, but not depend on any other shared object being present, as otherwise it requires (r)path handling. Similar becomes the case in terms of python fat-binding extensions etc.

[meghprkh]

Please let me know what I can do to help with this ticket, if I should create a JIRA issue etc