[Insight] Update to support Cloud

[0xW1sKy]

method updates:

init

• updated to check for cloud parameter and trigger separate init process for seamless cloud-relevant configuration.
• sets api_root parameter for on-prem to allow for single method of building urls within insight.py

all methods

• updated to use url_joiner(api_root, ) for single pattern across cloud & on-prem
• added cloud check and NotImplementedError to methods that are not available with Insight Cloud

addition of new methods:

__cloud_init

• uses __get_workspace_id to assemble api_root path
• sets default headers to {'Accept': 'application/json'}

__get_workspace_id

• uses ServiceDeskApi to get InsightCloud workspace Id