extrudeHelical does not have proper defaults

[z3dev]

If extrudeHelical() is called without options then the function will throw an error.

TypeError: Cannot read properties of undefined (reading 'pitch')
      at Object.extrudeHelical (/Users/z3dev/dev/jscad/jscad-object-api/node_modules/@jscad/modeling/src/operations/extrusionsextrudeHelical.js:37:16)

It looks like the default for pitch is not being recognized / set properly.