Handling multibyte character sets during migration

[CR# 353079] If you configure multibyte character sets after migrating data from system catalogs sysattributes and sysxtypes, the text columns in these catalogs are inconsistent with the multibyte character sets.

Workaround: Manually run dbcc fix_text on sysattributes and sysxtypes to make the text columns consistent with the multibyte character sets.