remove reliance on agoric run in shell path

[turadg]

Problem to be solved

A couple modules in the synthetic-chain package need to run builder scripts for core-evals. They do this now calling out to agoric run in a child process: https://github.com/search?q=repo%3AAgoric%2Fagoric-3-proposals%20%22agoric%20run%22&type=code

This creates a dependence on the shell environment.

Added context

Design

agoric run is implemented in JS. Have agoric-sdk export the necessary functions to do the work and have a3p import them.

[turadg]

This tech debt added work to Agoric/agoric-sdk#9945 in the form of a build failure: https://github.com/Agoric/agoric-sdk/actions/runs/10529314379/job/29176823312?pr=9945

As a stop-gap, the package could admit its dependence on agoric CLI