Fix: Support for user-defined module fmt for all compilers (#5441)

This PR fixes #5283
I added the corresponding test.

<small>By submitting this pull request, I confirm that my contribution
is made under the terms of the [MIT
license](https://github.com/dafny-lang/dafny/blob/master/LICENSE.txt).</small>

Dafny v4.6.0

Dafny v4.5.0

Dafny v4.4.0

Dafny v4.3.0

Dafny v4.2.0

Dafny v4.1.0

Dafny v4.0.0

Dafny v3.13.1

Dafny v3.13.0