WIP: Start SDK tests for delete_all_by_eq_bsatn

[kazimuth]

Description of Changes

This API used to be unimplemented and the SDK tests did not exercise it. Now it is implemented but while playing with blackholio I noticed the C# implementation was wrong.

For now I am going to fix blackholio by avoiding use of this API for now, but we should also correct the implementation and test it.

API and ABI breaking changes

None

Expected complexity level and risk

0

Testing

Working on adding tests. If someone is more familiar with the SDK tests I would appreciate help amending them.

[kazimuth]

This is almost entirely redundant with https://github.com/clockworklabs/SpacetimeDB/pull/2146 (merged just before and I didn't see) except that I wanna add a few more tests to that.

[CLAassistant]

All committers have signed the CLA.