fix: unwrap method call validator errors and add tests

[shanejonas]

Explanation

This removes the jsonrpc error wrapping that happens in the method call validator. Also adds a new error returned for when the parameter length is mismatched.

References

fixes this TODO item: #4784 (comment)

Changelog

@metamask/package-a

• : Your change here
• : Your change here

@metamask/package-b

• : Your change here
• : Your change here

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've highlighted breaking changes using the "BREAKING" category above as appropriate
• I've prepared draft pull requests for clients and consumer packages to resolve any breaking changes

[jiexi]

it seems a little weird to be testing against the actual schema that the multichainCallValidator is using under the hood. I understand what you're trying to get coverage on that file though. Are we still sure that we don't want to abstract the multichainCallValidator into a separate package?