Jackson 3 port

[TotallyMehis]

Jackson 3 is not out yet, but decided to try porting it to latest RC. I'm not super experienced with Jackson, but luckily this repo has plenty of tests. Let me know if this helps 😄

[nrayburn-tech]

I skimmed through this and it generally looks fine to me for now. A few considerations below before this gets merged, but nothing specific to your work. It just means this will probably sit for a while before being merged in.

• Jackson 3 uses Java 17, so that can be changed in this project with this.
• I don’t think it’s very common to use javax libraries with Java 17, so the javax validation support might be a candidate for removal.
• This won’t be compatible with Jackson 2. This project will either need to support 2 concurrent branches or move on to Jackson 3 and stop supporting Jackson 2. Before doing this, there’s some other outstanding issues/PRs that I think can be put into a release that still supports Jackson 2.
• As you mentioned, Jackson 3 is still only a release candidate. I don’t think this should be merged until a final Jackson 3 is available.

[Til7701]

I agree, this looks good.

• I think we should support Jackson 2 until either all projects have migrated or Jackson 2 is no longer maintained. Thus we should have a 0.2.x branch for Jackson 2 support and continue with Jackson 3 on master once it is released.
• I also agree that we should merge the requested features before we create the branch.

[TotallyMehis]

I have no problem keeping this open and updating it whenever master changes. It would probably make sense to do the Java 17 and javax changes in this PR, but we'll see :)