feat(plugin-oracle): support Oracle Database 11g

[datlechin]

Fixes #1425. Related: #483.

Oracle 11g (11.1 and 11.2) servers now connect. Previously the pure-Swift driver rejected anything below 12.1, so 11g failed with a raw OracleSQLError(code: serverVersionNotSupported). Validated against a live Oracle 11.2.0.2 XE instance: connect, authenticate, and fetch multiple rows with VARCHAR2, NUMBER, and DATE columns.

What's here

Oracle 11g support (driver work merged in TableProApp/oracle-nio#1):

• Bumps the oracle-nio pin to the merged tablepro-main commit, which lowers the protocol floor to 11.1 and implements the legacy O5LOGON auth, Accept-packet, execute, and OER-status wire formats that pre-12.1 servers use. 10g and earlier stay unsupported (they use the O3LOGON handshake).

Clearer connection errors:

• Every place you open a connection now routes failures through the plugin diagnostic dialog, the same detailed dialog with suggested fixes that Test Connection shows. Before, only Test Connection did; opening a saved connection showed a generic alert.
• Oracle failures no longer surface the driver's raw redacted message. "Server Version Not Supported" now means the database is older than 11.1, and the "Connection Dropped" dialog points at Native Network Encryption (which the thin driver cannot negotiate) as the likely cause.

Docs: docs/databases/oracle.mdx corrected to 11.1+, pure-Swift, no Instant Client (the page previously claimed OCI, contradicting itself).

Notes

• Not in this PR: a SID connection option. Oracle currently puts the service name in the main path field, so adding SID cleanly needs a small connection-form rework. Tracked separately.
• The connect-error routing change benefits any plugin with a diagnostic, not just Oracle.