Add connection information to exceptions

[andy-maier]

Today, pywbem exceptions do not contain any information to relate the issue to a server connection. This would be particularly useful for connection-related issues, but also useful for e.g. CIM errors.

The idea is to add fields to the exception for the connection id and for the server url. Probably it makes sense to have that in the message, at least for connection related exceptions.

[andy-maier]

PR #1287 (merged) addresses this issue for most cases, except the exceptions raised in tupleparse.
Another PR will address the remaining cases.

[andy-maier]

The solution for the remaining cases of raising pywbem exceptions is as follows:

• For the tupleparse module: Put the module-global parse_...() and most other functions into a new class that stores the connection ID as an instance attribute.
• For the tupletree module: Add the connection ID as an additional optional argument to the three relevant functions of that module that raise exceptions.

[andy-maier]

PR #1348 addresses the remaining occurrences of raising pywbem exceptions, in tupleparse and tupletree. This completely fixes this issue.