Tests | Additional test cases

[cheenamalhotra]

Summary of all missing cases

#	Constructor	Input	What to assert
1	1-arg (string)	null	ApplicationClientId == SqlClientId, UseWamBroker == true
2	2-arg (callback, string?)	non-null callback + SqlClientApplicationId	UseWamBroker == true
3	2-arg (callback, string?)	null callback + custom ID	No throw; _deviceCodeFlowCallback == DefaultDeviceFlowCallback
4	Options ctor	ApplicationClientId = SqlClientId, UseWamBroker = true	UseWamBroker == true
5	Any ctor with non-null callback	explicit callback	_deviceCodeFlowCallback is that exact instance
6	Any ctor without callback	omitted/null callback	_deviceCodeFlowCallback is DefaultDeviceFlowCallback, not null
—	Duplicate	Ctor_ApplicationClientId_EnablesWamBroker	Remove in favour of Ctor_AppClientId_SqlClientId_EnablesWamBroker

Originally posted by @paulmedynski in #4288 (comment)