SQL Server RevEng: No ForSqlServerIsClustered(false) on NONCLUSTERED PKs

[smitpatel]

At present we add Clustered annotation on index when its clustered.
Points to remember,

1. By default PK is clustered but we never scaffold index for it explicitly.
2. There can be only 1 clustered index. Which means that we may need to set clustering false on PK if there is another index.
3. Annotation should be set only when we need to specify fluent API else it should remain null.

This will make processing of clustered index accurate.