Fixes incorrect Jackson imports in Java templates used in ApiClient.java when useJakartaEe=true

[JochemKuijpers]

This PR aims to fix a compiler issue I ran into when generating java code from an API spec.

The generated code imports com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider in ApiClient.java, which is the javax package, while my project uses jakarta and requires com.fasterxml.jackson.jakarta.rs.json.JacksonJsonProvider. Upon searching, this seems to be a long-standing issue in this specific configuration, I was able to find at least one issue directly referencing it: #15875.

Upon digging deeper, it seems the generated ApiClient.java file in my particular configuration (using the apache-httpclient library) doesn't even use the imported class, so in this specialized template it can even be omitted, as is the case in a secondary issue reported as #18289.

The PR does not add any new template parameters, but instead switches over the useJakartaEe parameter already exposed to select the appropriate Jackson package to import. This should fix this problem for all Java templates. In addition, I have removed the unused import for the apache-httpclient specifically, since it is not needed.

Tagging committee members as requested in the checklist:
@bbdouglas @sreeshas @jfiala @lukoyanov @cbornet @jeff9finger @karismann @Zomzog @lwlee2608 @martin-mfg

I can currently work around the compile issue in my project through an overwritten template file in my template folder where I've fixed this locally, but this PR should fix it for everyone else running into the same issue.

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[wing328]

Thanks for the PR but your commit (as shown in the Commits tab) is not linked to your Github account, which means this PR won't count as your contribution in https://github.com/OpenAPITools/openapi-generator/graphs/contributors.

Let me know if you need help fixing it.

Ref: https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-can-i-update-commits-that-are-not-linked-to-my-github-account

[JochemKuijpers]

Thanks for the heads-up @wing328 -- incorrect git config on my part. Should be fixed now 🙂
Let me know if you need anything else to get this merged!

[JochemKuijpers]

@wing328 sorry for the poke, but is there anything else that needs to be done or can this be merged?

[beikov]

I need this too. Please merge and create a new release when possible.

[wing328]

@JochemKuijpers thanks for the PR. I'll run some tests and try to get it merged before the upcoming v7.6.0 release.

[wing328]

tested locally and the output compiles (except jaxrs-cxf-extended, which has the same issue in the latest master anyway, we will look into it separately)