[Retiarii] Retry a failed multi-model trial by disabling CGO in CGOExecutionEngine

[hzhua]

When multiple models is merged into one trial by cross-graph optimization (CGO), there are multiple reasons that can cause trial failure:

1. The CGO policies wrongly merge multiple models, e.g., GPU OOM;
2. The mutated model is wrong even without CGO, e.g., wrong shape in mutation.

A failed multi-model trial CGOExecutionEngine should be dissembled into multiple single models, each of which should be submitted independently as a single trial.

This PR depends on #4086. #4086 should be first merged before this PR.