Fixes azure account detection to work with email address

[cheenamalhotra]

Fixes command-line behavior where email address wouldn't work when trying to connect using Azure MFA.

E.g.
azuredatastudio --server <serverName> --authenticationType AzureMFA --user <email address> --command connect

Before:
Launches ADS, but doesn't connect immediately, opens connection dialog instead. Below errors are captured in logs:

Could not find Azure account with name undefined
Failed to connect due to error: Error

After:
Launches ADS and creates a new connection if email address is found associated with an Azure account.

[coveralls]

Pull Request Test Coverage Report for Build 7491693434

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 41.762%

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Totals
Change from base Build 7482522687:	0.0%
Covered Lines:	30827
Relevant Lines:	69073

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💛 - Coveralls