Enact proposal through governance message

[mhofman]

What is the Problem Being Solved?

We currently have 2 main mechanism to trigger JS execution by governance:

• core eval, which executes some arbitrary code in the bootstrap vat
• "core proposal" which automatically build and publish bundles and execute the proposal as a core eval

The former can be performed at any time by submitting a CoreEval governance proposal. While the latter leverages the CoreEval logic, it can currently only be triggered during a chain software upgrade (or at chain bootstrap). Furthermore core proposals can accept options when being built into submitable core evals, but not when they are executed during upgrades.

Description of the Design

A new swingset governance message for enacting a core proposal, which would build and execute a core proposal script included in the chain software release

An ability to pass parameters when building the core proposal, for both this new message, and possibly for the proposals executed during chain software upgrade (less needed)

Security Considerations

None more than the existing mechanism

Scaling Considerations

None

Test Plan

a3p integration. would remove the need of core eval layers like #8907

Upgrade Considerations

See above

[mhofman]

This could be used to trigger adding new collateral without having to publish code (agoric-labs/ag-power-tools#8), or trigger vat termination.

[mhofman]

Should likely be submitted as a cosmos.gov.v1.MsgSubmitProposal message (see #9869)