Support unsigned types are available in sql

[guswynn]

See https://materializeinc.slack.com/archives/CMHDK0DK8/p1654625087694429

• [ ] implement the proposal as outlined in https://github.com/MaterializeInc/materialize/issues/7629
• [ ] Fix the bitwise cases for INCLUDE OFFSET introduced in https://github.com/MaterializeInc/materialize/pull/12879

[JLDLaughlin]

this is a platform blocker because mz_offsets are currently cast from u64s to i64s in the PR that Gus linked above.

I think I'm going to ask @jkosh44 to pick this up in a few weeks, after the following other items are complete: correctness property #1 and SQL limits.

[guswynn]

thanks @JLDLaughlin !

[chaas]

@guswynn Both items in the todo list are complete, so marking this as done.