Make the Driver Compatibility Matrices more obvious in their support for connecting to "unsupported" versions

Customers raise questions as a result of supportability for new versions of MongoDB from "older" drivers (such as https://www.mongodb.com/community/forums/t/mongodb-5-0-support-in-mongocxx/152102).

This is due to the compatibility matrices not clearly identifying that older drivers "can still connect and interact with this version but newer features would not be supported". For example in https://docs.mongodb.com/drivers/cxx/#compatibility, the C++ driver doesn't show ANY support for MongoDB 5.0, which is confusing to customers.