crd: remove field transformation struct and its usages

[muvaf]

Description of your changes

FieldTransformation is the one and only struct passed as result from one generator to the other. As mentioned in #9 and #4 (review) , the information it conveys is already available. So, this PR removes it and gathers that information from config.Resource, using it as the source of truth for such info like all other mechanisms.

Fixes #9

I have:

• Read and followed Crossplane's contribution process.
• Run make reviewable to ensure this PR is ready for review.
• Added backport release-x.y labels to auto-backport this PR if necessary.

How has this code been tested

Only the following diff is reported in the examples in main of provider-aws:

[muvaf]

I separated reference field name calculation into its own PR because it seems like this PR will take a while to merge since it touches very similar places #15 touches.

[sergenyalcin]

LGTM! @muvaf It seems that this PR touches some places that are related the example generation. I have not very much context on this. So maybe @ulucinar's review on this part can be more accurate. But, for unblocking the apigateway2 PR, I approve this. Thank you very much.

[muvaf]

@sergenyalcin thanks! I think it's not a risky change but there are conflicts with other example gen PR so I'll wait that before merging. #48 is the blocking PR actually.

[sergenyalcin]

@sergenyalcin thanks! I think it's not a risky change but there are conflicts with other example gen PR so I'll wait that before merging. #48 is the blocking PR actually.

@muvaf Got it! I realized that the PR was separated after I started the review :) I will also review the blocking PR. #48

[sergenyalcin]

Thanks @muvaf I did a code review and as far as I understand the most important file is example.go In another files, mainly, changes are related the changed function call. This PR looks good to me generally.

As I said that before, these changes are related with your before works together with Alper. So apart from high-level architectural part, I focused on the code review.