Test fails after removing `unused files`

[bourgeoa]

@michielbdejong
Since last commit to main 387762e
some tests are failing

> jest

 FAIL  test/unit/util/HeaderUtil.test.ts
  ● Test suite failed to run

    test/unit/util/HeaderUtil.test.ts:2:29 - error TS2307: Cannot find module '../../../src/util/Header' or its corresponding type declarations.

    2 import { ContentType } from '../../../src/util/Header';
                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~
    test/unit/util/HeaderUtil.test.ts:15:8 - error TS2307: Cannot find module '../../../src/util/HeaderUtil' or its corresponding type declarations.

    15 } from '../../../src/util/HeaderUtil';
              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~