Draft: PoC: Make all IDs to be shardable

What does this MR do?

This aims to support horizontal sharding for all IDs. Allowing to create many logical databases with distributed identifiers.

This uses:

• all tables now have bigint
• this requires all tables to use bigint, where we look at around 640 columns to be converted
• uses schema defined in #329300 (comment 564024347)

Closes #329946 (closed)