Add RFC 10008 (QUERY HTTP method) support

[desiderantes]

This change introduces support for RFC 10008: The HTTP QUERY Method.

Although initially described as just a "safe GET with a body", the QUERY method unlocks the ability to send complex payloads that do not represent a mutation, and can be handled in a safe, idempotent way. Think of it as a replacement for usecases like complex query parameters in URLs, POST requests that do not mutate anything (but have to be treated as such by all other components in the network roundtrip, so no caching, etc.), and non-mutating HTML Form submission that can use an appropriate encoding for the body.

Fixes #32975

[desiderantes]

Will keep this one in draft until the standard is published, but I'd appreciate any review

[desiderantes]

the draft has been approved for publication, so I'm marking this PR as ready for review.

[bclozel]

the draft has been approved for publication, so I'm marking this PR as ready for review.

That's a 404 now, we can use https://www.rfc-editor.org/info/rfc10008/ instead as a reference.

[anupamsingh24]

In which spring boot version will this change be available?

[bclozel]

We will do a thorough review of this PR and synchronize with other Spring projects. There are many aspects to consider (like the fact that @QueryMapping already exists in spring graphql) but we would like to support this in time for Spring Framework 7.1 in November. We will post updates here, no further changes or reviews are needed at this time on this PR.

[desiderantes]

I understand a lot of people want this to be merged, after all, it is a very useful addition if I do say so myself. However, at this point approvals from non-committers are becoming background noise, it is hard to know if they're showing support, or if it's a form of spam. You can leave a reaction on the PR description, or track the ecosystem adoption in other projects and get involved in other areas. You can also leave a comment if you spot any issues with this implementation. Otherwise I think it'd be best to heed the comment from @bclozel and await for further updates. Thanks for your interest!