Schema Compare fails for Azure database using AAD auth

[udeeshagautam]

Insiders build
Version: 1.6.0
Date: 2017-12-15T12:00:00.000Z
VS Code 1.31.1
Electron: 3.1.8
Chrome: 66.0.3359.181
Node.js: 10.2.0
V8: 6.6.346.32
OS: Windows_NT x64 10.0.17763

Steps to Reproduce:

1. Connect to an Azure Server using AAD
2. Start schema compare for a database inside this server same connection
3. Fill in the details and click compare

Expected:
Should show diff

Actual:
SQL tools service throws null ref exceptions

Notes:
Two things to fix here,

1. Should check for null schema models
2. Connection info created through AAD auth should work in schema compare APIs

[udeeshagautam]

Moving to planning as Kim is working on it