🐛 BUG: Some SDK settings are miscategorised

[ReubenFrankel]

Not sure of all that are missing from the Hub list of SDK setttings, but for example: batch_size_rows is listed as a plugin-specific setting for target-postgres, despite it not being explicitly defined in its config schema.

Side note: this target does explicitly define activate_version, which is also an SDK setting (and also missing from the Hub list), but I think the logic is correct here - i.e. if a plugin built with the SDK redefines an SDK setting (by name), then always treat it as a plugin-specific setting.