Support authSource and authMech Parameters for MongoDB Connections

NetBrain currently supports only standard username and password authentication for MongoDB connections, with no ability to specify an authSource database or an authentication mechanism (authMech) required by certain MongoDB deployment configurations. This enhancement would add configurable authSource and authMech fields to the MongoDB connection settings, allowing administrators to align NetBrain with their specific MongoDB authentication requirements. Customers running MongoDB environments that require a designated authentication database or a non-default authentication mechanism would benefit from successful connectivity without needing workarounds or configuration changes on the database side.