Add a parameter to allow ExtKeyUsage field usage from a role

[Viper61]

As discussed in #21549, there is some use cases where allowing expanding ExtKeyUsage is adequate (eg containers).
This PR adds a new configuration option on ACME to allow usage of the ExtKeyUsage field defined within a role.

[hashicorp-cla]

All committers have signed the CLA.

[stevendpclark]

Thanks @Viper61 for the submission.

Looks good to me, a test for the new behavior would be nice, but we can add that after the fact, and note to myself, docs need to be updated.

[Viper61]

Thanks for the review.

Both rewording you suggested were applied.
The new parameter was also included in website/content/api-docs/secret/pki.mdx

I'm trying to write a proper test. Sadly my lack of knowledge in Golang is causing me trouble.
I haven't been able to do something working/I'm happy with. I'll keep you posted when I'm able to do something good enough.

[stevendpclark]

Thanks for the extra work @Viper61, we can handle writing of the test if you wish, let me know either way.

We will also tweak a few nits such as renaming the field to allow_role_ext_key_usage, and internal config variable to AllowRoleExtKeyUsage to be better aligned with existing fields/codebase. Sorry I missed these in the original review.

[Viper61]

No problem @stevendpclark. I updated the variables accordingly :)

Regarding the test, either it's always showing ok, either I'm not having it running at all.
I guess I can let you handle it if it's fine for you? I'll make sure to follow that closely. I will learn something there.

Edit : Rebased the PR on current main

[stevendpclark]

No problem @stevendpclark. I updated the variables accordingly :)

Much appreciated!

Regarding the test, either it's always showing ok, either I'm not having it running at all. I guess I can let you handle it if it's fine for you? I'll make sure to follow that closely. I will learn something there.

No worries, I just pushed an updated unit test and I tweaked some of the UI label text a bit in a commit pushed to your branch.

[stevendpclark]

Thanks again @Viper61 for the submission, this should make it into the next minor Vault release.