[#737] Add `runCode` to Cleveland

Description

Problem: In morley-metadata-test, we want to be able to run off-chain-views in Cleveland emulator & network tests.

Solution: This can be done by adding a new runCode action to cleveland. In network tests, this calls the /run_code endpoint. In emulator tests, we use the Runtime engine to emulate originating the contract and then calling it, without saving the result in the global state at the end.

Related issue(s)

Resolves #737 (closed)

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