Write Data Sources and Roll Policy

[tristanlatr]

Describe
The library should handle a easy way to Write Data Sources and Roll Policy.

May be create a DevTree.write_policy() method?
May be also create a DevTree.add(write_policy=True) argument that will call the method? (See #82 for another DevTree.add() improvement)

SIEM and msiempy versions:

• msiempy: 0.3.5

Additional context
The APIs that need to be called are dsWriteThirdpartyConfig, plcyRollPolicy, and miscJobStatus