SAK-48241 Kernel remove pre-2008 Cruft to convert XML serialized data to BNARY_ENTITY data

[jonespm]

This is an updated/rebased/more stuff removed revision of #11142 that was merged and reverted.

It is still draft as the question of what to do about the UTF-8 check is still open.

SAK-48241

Some conversion code is retained to convert XML -> BINARY_ENTITY in the CONTENT_COLLECTION table right after autoDDL. The CONTENT_RESOURCE and CONTENT_RESOURCE_DELETE tables now have dispensed with the XML column completely.