Allow passing non-generic HttpMessageConverter in AssertJ JSON test support

[sdeleuze]

As a follow-up of #33118, the following classes should be updated to allow providing a SmartHttpMessageConverter as an alternative to current GenericHttpMessageConverter arrangement in the following classes:

• org.springframework.test.json.AbstractJsonContentAssert
• org.springframework.test.json.AbstractJsonValueAssert
• org.springframework.test.json.JsonContent
• org.springframework.test.web.servlet.assertj.AbstractMockHttpServletResponseAssert
• org.springframework.test.web.servlet.assertj.DefaultMvcTestResult
• org.springframework.test.web.servlet.assertj.MockMvcTester
• org.springframework.test.json.JsonPathValueAssert
• org.springframework.test.web.servlet.assertj.MvcTestResultAssert
  FYI we are considering using this contract for the upcoming Jackson 3 support.

End-users may also provide non-smart non-generic HttpMessageConverter, so maybe we should just use HttpMessageConverter arguments + instanceOf checks to support the 3 variants, check 4555384 for inspiration.

[snicoll]

I am working on this to attempt to minimize the code change necessary to support SmartHttpMessageConverter as my need do not require the added contract.

[snicoll]

As discussed in #33148, this ask made me realize we should improve things in a way that this issue is no longer relevant.

Superseded by #33148.