Enable logging for incoming server requests

[purusharths]

The server now prints out incoming requests with some associated metadata
Function call changed to: UMBridge.serve_models([testmodel], 5232, true) with the last Bool argument acting as a trigger to initiate logging (default argument is false).

As of now, there's an extra level of verbosity with all Evaluate calls being printed out -> a possible resolution could be to export the logs to file instead. tail -f <filename> | grep "keywords" can then be used to filter for incoming requests. OR use a separate argument to enalbe logging for evaluate all together?
@linusseelinger thoughts?

[annereinarz]

@purusharths Can you explain the todo note on changing input to evaluate? I'd prefer not to merge in code with active todos.

[purusharths]

@annereinarz the TODO mentioned in the code is the same as my comment in this PR:

As of now, there's an extra level of verbosity with all Evaluate calls being printed out ->  ... 
use a separate argument to enalbe logging for evaluate all together?

PS: I'll close this PR and add a new one without duplicate commits from #13