Update rdbms-types to support Date / Tmestamp

[tyler-harpool]

Purpose of this PR is to add datetime and timestamp support.

[rylev]

Thanks for the PR! Adding this will constitute a breaking change so we'll need to make sure we do accept this at the right time. We're figuring out what changes to land in Spin 3.0 so this will definitely be a good candidate for discussion. In the meantime, we appreciate your patience while the discussion happens.

[itowlson]

Note this will also require updating the conversion routines in the MySQL and Postgres factors.

[michelleN]

Note this will also require updating the conversion routines in the MySQL and Postgres factors.

@tyler-harpool - do you have bandwidth and/or interest in contributing the runtime bits for this @itowlson described in the next week or so (so that we can ensure it gets into Spin 3.0)? If you do, that's great. If not, we can make arrangements to have someone else contribute that bit. Just lmk! Thanks!

[tyler-harpool]

Would love to handle this, but bandwidth is limited as I'm on holiday/PTO. I'm happy to punt as this would be a challenge on my side. Happy to do anything to assist.

[itowlson]

I'm closing this in favour of #2890 - @tyler-harpool is aware. Thank you again Tyler for getting this process under way!