Load Properties from Connection String

It should be possible to configure the ClusterEnvironment (and CoreEnvironment) from connection properties parameters, so when passed in through the connect method they are picked up automatically.

Note that it is expected that not all properties available on "our" environment are exposed through the connection string. Rather, we need to figure out which connection string properties are available in libcouchbase and map them to the properties that make sense on our environment.

There is already infrastructure in place which shows how it can be done: https://github.com/couchbase/couchbase-jvm-clients/blob/master/core-io/src/main/java/com/couchbase/client/core/env/ConnectionStringPropertyLoader.java

The property loader is already loaded by default https://github.com/couchbase/couchbase-jvm-clients/blob/master/core-io/src/main/java/com/couchbase/client/core/env/CoreEnvironment.java#L108

Note that the ConnectionString class might need to be modified, its param handling hasn't been exercised well in the past.