[WTF-2710]: Fix unit tests failing on ValueStatus import

[alihcsumer]

Checklist

• Contains unit tests ❌
• Contains breaking changes ❌
• Did you update version and changelog? ❌

This PR contains

• Bug fix

What is the purpose of this PR?

...

Relevant changes

Unit tests run via pluggable-widgets-tools test:unit:web fail to load any test suite whose module graph imports a runtime value from the mendix package.
The suite errors out before any test runs with "This package should not be used in the runtime."

[weirdwater]

I like the approach proposed in !192 better, since it follows a pattern we already use for mocking other parts of the mendix package.

Additionally I would ask to add some form of type checking. In this example the mocked enum is checked for completeness. This will throw an error when the mock misses a member.

export const FormatterType: { [t in keyof typeof mendix.FormatterType]: string } = {
    Number: "number",
    DateTime: "datetime",
}

I tried to check for both completeness and consistency, but I was not able to index over the enum without importing the value.