refactor(base-zone,store): prepare for migration to endo repo

[erights]

closes: #XXXX
refs: #8745

Description

By removing dependencies from this pair to anything else in agoric-sdk, we prepare to move this pair of packages from the agoric-sdk repo to the endo repo.

From internal discussions, it is clear that the agoric-sdk repository and the endo repository will remain separate at least for the immediate future, and possibly forever. However, for the current boundary between the two to make sense, there remain two misplaced packages: @agoric/base-zone and @agoric/store. This PR just prepares them to make the migration, but does nothing else.

Additional motivation (that finally pushed me to start this) is @dckc's comment at #8745 (comment) . Once prepare-revocable.js is refactored to depend on zones, it will no longer be limited to durable objects, but can be used with any zone. At that point, it should live in the endo repo. (The rest of #8745 , which is about ownables, should remain in agoric-sdk because it uses zoe concepts.)

Security Considerations

For this PR itself, none. For the migration it prepared for, likely none as well, but we'll be explicit about that then.

Scaling Considerations

For this PR itself, none. For the migration it prepared for, likely none as well, but we'll be explicit about that then.

Documentation Considerations

For this PR itself, mostly none. For the migration it prepared for, likely none as well, but we'll be explicit about that then.

I did add a note to the README of both packages explaining that these will be migrated to the endo repo.

Testing Considerations

For this PR itself, none. For the migration it prepared for, likely none as well, but we'll be explicit about that then.

Upgrade Considerations

For this PR itself, none. For the migration it prepared for, likely none as well, but we'll be explicit about that then.

@ivanlei , I added you as a reviewer to judge when this PR could be merged without being too disruptive.

[dckc]

prepare for migration to endo repo

suggested clarification: remove dependencies on @agoric/* modules

I've been struggling to understand which end is up here. If I'm reading this
right, that's the gist of it.

Looks plausible.

But without a clear sense of how this gets released / deployed,
I leave it to others to approve.

[michaelfig]

LGTM!

[michaelfig]

For release, I understand that these packages will be copied to Endo, then after a new Endo sync, these packages will be updated to be stubs that import the Endo versions.

[erights]

prepare for migration to endo repo

suggested clarification: remove dependencies on @agoric/* modules

I decided against changing the summary string, because I'd rather summarize the purpose than the mechanism. But I did add this clarification to the beginning of the PR description.