chore: DRY up the two codegen subclasses

[paulirish]

Description

I saw https://github.com/checkly/puppeteer-recorder/pull/98 and was interested. I saw that there was barely any difference between the PPTR and PW codegen files so I tried my hand at moving the implementation back into the base class to get some Dont Repeat Yourself goodness.

also, this is a PR against #98.. Tho, if you want to merge 98 first, I can change the merge target to master.

For reviewing it might be useful to compare this branch to master. There you can see the codegen base class edits a bit more clearly.

Type of change

• [X] aesthetic refactor :)
• [x] Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Ran the existing tests

Checklist:

• [x] My code follows the style guidelines of this project. npm run lint passes with no errors.
• [ ] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes. npm run test passes with no errors.
  • well, the forms and attributes tests fail on my machine, even on master. didnt look into it but i dont think my PR should change anything there.

[tnolet]

@paulirish thanks for chipping in here. Much appreciated! @maxigimenez Is the driving force here so we will review and follow up ASAP.

[maxigimenez]

Thanks @paulirish!, LGTM 👍