Proto/Michelson: remove the script from the error message for runtime error

Context

When a runtime error occurs during the interpretation of a Michelson script, the script is passed in the error message. This makes block metadata quite large in practice for no good reason.

This MR removes the script from the error message. It does not however patch the client to fetch the script from the address so the error-reporting abilities of the client are reduced in this MR.

Manually testing the MR

This MR can be tested in a similar way as !4180 (merged). To see the effect of this patch, at the very end of the tezt test of !4180 (merged), the errors field should be fetched instead of the status one. The errors object has a contract_code field on Hangzhou and Ithaca but not on Alpha.

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, the Development Version section of CHANGES.md for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR