CAST bind values against SQL Server sys into NVARCHAR

CAST bind values against SQL Server sys into NVARCHAR

Ensured that the queries used to reflect indexes and view definitions will
explicitly CAST string parameters into NVARCHAR, as many SQL Server drivers
frequently treat string values, particularly those with non-ascii
characters or larger string values, as TEXT which often don't compare
correctly against VARCHAR characters in SQL Server's information schema
tables for some reason.    These CAST operations already take place for
reflection queries against SQL Server ``information_schema.`` tables but
were missing from three additional queries that are against ``sys.``
tables.

Fixes: #4745
Change-Id: I3056533bf1a1e8ef17742879d369ab13f8b704ea