Adds Oracle as a data source through rust-oracle (ODPI-C), which loads the user's
Oracle Instant Client at runtime; the client is not bundled. The Options tab takes
the Instant Client directory (empty: ORACLE_HOME or the system library path).
Covers connecting, the schema tree, consoles with PL/SQL blocks, table editing,
Generate DDL (DBMS_METADATA), Explain Plan (PLAN_TABLE), Oracle-specific SQL
generation and completion, and jdbc:oracle:thin URLs.
Review fixes: PL/SQL units keep their closing END; (the server rejects a block
without it), a subprogram's declarations no longer split it, and packages end at
a / line; LOB cells are read through locators (they showed as null and broke
Generate DDL); ORA-01005 prompts for a password; the Instant Client directory is
optional in the dialog.
Co-authored-by: boenkkk <17746937+boenkkk@users.noreply.github.com>
