feat: support swap to atomically rename 2 MVs

[fuyufjh]

Is your feature request related to a problem? Please describe.

As title. See slack for background.

Describe the solution you'd like

ALTER MATERIALIZED VIEW mv_1 SWAP WITH mv_2;

Describe alternatives you've considered

No response

Additional context

Note that it's different from #14223, which discusses swapping 2 schemas.

Note that it's also different from changing an upstream of an MV, which requires much more engineering effort and is a kind of ALTER MV.