Add support for MongoDB Atlas Serverless

[realugbun]

MongoDB has introduced a new serverless offering.

When the dns is queried it returns a TXT record containing authSource=admin&loadBalanced=true The loadBalanced parameter is unique to serverless so drivers that have not been updated throw an error that they get an invalid parameter from the DNS TXT record. There is no work around because as Mongo controls the DNS records.

This connection string throws an error stating "Could not open connection to database" with an explanation about the TXT record.
mongodb+srv://example.mongodb.net/test?retryWrites=true&w=majority

Caused by: com.mongodb.MongoConfigurationException: A TXT record is only permitted to contain the keys 
[authsource, replicaset], but the TXT record for 'example.mongodb.net' contains the keys [loadbalanced, authsource]
	at com.mongodb.ConnectionString.<init>(ConnectionString.java:388)
	at liquibase.ext.mongodb.database.MongoConnection.open(MongoConnection.java:104)