The schema name should be configurable

[rdlrt]

Currently, following install scripts as-is ends up with hard-coded schema cardano which could be a very generic name creating conflict.
A better workflow could be users setting up schema name as an input variable during install.

[Fell-x27]

A better workflow could be users setting up schema name as an input variable during install.

Due to the specifics of the extension build pipeline, this will be somewhat tricky to achieve. It will require dynamically modifying SQL migrations during installation.

In the future, it might make more sense to simply replace the schema with pg_cardano to reduce the likelihood of collisions rather than making it dynamic. This is especially relevant given that the schema is explicitly mentioned in the documentation examples.