chore: client library inheritance fixes and simplifications

[allenporter]

Update the base classes to use the abc package, which provides the infrastructure for defining abstract base classes. Remove variables that are overridden in multiple places so that variables are only set once in the class hierarchy. The fixes include:

• Use @abstractmethod to avoid needing the raise NotImplemented reducing untested lines of code
• Set _endpoint only once, rather than multiple times. Removed the places where it is not used. (Question: Local commands use it when secured with "abc" but does it do anything?)
• Set _logger once for each client in the client itself so that the log messages are associated with the actual client being used. This will let us tell the difference between a local client disconnecting and a cloud client disconnecting which is difficult to do today
• Remove duplicate definition of _send_msg_raw in both the v1 mqtt client and the base mqtt client

Issue #228

[Lash-L]

commitlint gets mad if the subject is capatilized, idk why.I've just never changed it. Semantic release I don't believe requires that to be the case

[Lash-L]

Looks good, a good bit of redundant code removed