feat: Add function to find product identification helpers inspecting the tree

[juan131]

Description of the change

This PR adds a new exported method to ProductTree type in the csaf package: FindProductIdentificationHelpers. This method iterates over the product tree and find the product identification helpers associated to a given product id.

Benefits

Easier to obtain product identification helpers given a product id.

Possible drawbacks

None

Applicable issues

• closes Add an utility method on the advisory framework to fetch product identifiers #484

Additional information

N/A

[juan131]

cc @tschmidtb51 @mpermar

[tschmidtb51]

@juan131 Thank you for your contribution.

The implementation is currently missing the evaluation of the items in relationships (which can also define product_identification_helper). See https://github.com/csaf-poc/csaf_distribution/blob/v3.0.0-rc.1/examples/purls_searcher/main.go as example.

[juan131]

Thanks for the advice @tschmidtb51 ! Implemented at 4338f45

[tschmidtb51]

I'm currently on a business trip - so it might take a while for me to review it.

[juan131]

Friendly reminder to review this PR when you find the slot for it @tschmidtb51
Thanks in advance

[tschmidtb51]

Thank you for your contribution. We discussed it today.

As it basically puts the implementation of the example in a more generic case, please also adopt the example to use the new library function.

Also @s-l-teichmann had an idea about callbacks that might be helpful in the library. @s-l-teichmann please explain

[juan131]

Example adapted at 2e9d4ad @tschmidtb51

[juan131]

@s-l-teichmann @tschmidtb51 friendly reminder

[tschmidtb51]

@s-l-teichmann Please have a look

[s-l-teichmann]

I will have a look at this.

[s-l-teichmann]

Looks fine to me. The only thing I don't like is the direct creation on the helpers slice.
@juan131 I send juan131#1 to your repo.
But this is minor.

[s-l-teichmann]

See juan131#1

[juan131]

Thanks for the feedback @s-l-teichmann ! I applied your suggestions in the PR

[s-l-teichmann]

LGTM

[JanHoefelmeyer]

LGTM

This is implemented by now.

[juan131]

Thanks everyone for you help!