Feature/sql hana write

[ness-david-dedu]

Adds hana as a supported driver for sql_insert (output/processor), backed by github.com/SAP/go-hdb.

• New hana entry in driverField enum (conn_fields.go), DSN format hdb://[user[:password]@]host[:port][?param1=value1&...], question-mark placeholder
  style.
• sqlOpenWithReworks maps hana → underlying hdb driver name for database/sql.
• New upsert bool field on sql_insert: when true (and driver is hana), emits UPSERT … WITH PRIMARY KEY instead of INSERT INTO — requires a primary key on
  the table, updates matching rows instead of inserting, avoids duplicates on retry.
• New hanaWriter (output_sql_insert.go) implementing go-hdb bulk insert/upsert batching, active only when driver == "hana"; all other drivers unaffected.
• Registered in public/components/sql/package.go (driver import) and internal/plugins/info.csv (sql_driver_hana, community, not yet certified for cloud).
• Docs regenerated for sql_insert/sql_raw/sql_select (input/output/processor/cache) reflecting the new driver and upsert field.
• Added go-hdb to go.mod/go.sum.
• Added benchmarking harness (internal/impl/saphana/bench/saphana-write/): Taskfile, docker-compose (local Kafka), benchmark_config.yaml (Kafka →
  sql_insert upsert into HANA), and a Kafka load generator (load/main.go) for throughput testing against a real HANA instance.