oracledb thin client - better support executing SQL script files

[amochin]

I had some issues execution long SQL scripts with an Oracle DB using the "Connect Using Custom Params" keyword and the python oracledb module (see #173 for a connection example).
Unfortunately I can't tell exactly anymore, what it was.
Anyway there should be more tests and better support for running longer SQL scripts - at least in the native support for the oracledb thin client (planned for future).
Here are the oracle docs about it:
https://python-oracledb.readthedocs.io/en/latest/user_guide/sql_execution.html

[amochin]

Parsing the SQL script files was pretty much improved in 46d6120.
In case of particular troubles a new issue should be opened.