Fix CORE-2178 Use correct database collation

Fixes CORE-2178: https://liquibase.jira.com/browse/CORE-2178

MSSQLDatabase.isCaseSensitive() uses the system collation rather than the database collation to determine whether or not the database is case-sensitive. That is fixed by checking DATABASEPROPERTYEX(<catalog>, 'collation').

Also, MSSQLDatabase.getdbcSchemaName() always converts to lower case. That causes a false negative on a case-sensitive database when checking to see if the lock table exists.

I am not nearly familiar enough to understand the full impact of this change, but it does seem to fix the problem we are having on SQL Server 2012.