Constructing a codebook builder with codebook is not possible

[schmidmt]

Describe the bug

When constructing a CodeBookBuilder, the class method .codebook fails when providing a codebook built with lace.Codebook.

Is this a regression?
No.

To Reproduce

import lace

def test_empty_codebook_builder():
    codebook = lace.Codebook("empty")
    _builder = lace.CodebookBuilder.codebook(codebook)


test_empty_codebook_builder()

Fails with

TypeError: argument 'codebook': 'Codebook' object cannot be converted to 'Codebook'.

Expected behavior

A working CodebookBuilder should be created.