Specify core proposals in upgrade handler

[mhofman]

What is the Problem Being Solved?

#8112 added support to run core proposals during a chain software upgrade, however it relies on specifying the core proposals as part of the upgrade info when proposing an upgrade to a governance vote. That means the proposer needs to specify both the upgrade name, and the core proposal info, even though they're all distributed in a single software release.

We'd like to remove this need, and add the ability to specify core proposal info in the upgrade handler

Description of the Design

Add a helper which can be used by the golang upgrade handler to:

• parse coreProposals from the upgradeInfo, if any
• merge some base proposals specified by the upgrade handler

This could be a straightforward port of the equivalent logic added in #8370

Security Considerations

None

Scaling Considerations

None

Test Plan

a3p-integration

Upgrade Considerations

Yes