This PR fixes a long-standing issue where ShouldBindQuery() only recognized form struct tags instead of the more logical query tags, while maintaining full backward compatibility.

Problem

The query binding implementation was counterintuitive - when using c.ShouldBindQuery(), developers would naturally expect to use query:"field" struct tags, but the implementation only recognized form:"field" tags:

type User struct {
    Name string `query:"name"`  // This didn't work! ❌
    Age  int    `form:"age"`    // Only this worked ✅
}

// Using ShouldBindQuery() with ?name=John&age=30
// Result: Name="" Age=30 (query tag ignored)

This issue was originally identified in #3235 and fixed in PR #3236, but that fix was reverted in PR #3899 due to backward compatibility concerns.

Solution

The fix introduces a new mapQuery() function that supports both tag types:

1. Primary behavior: Recognizes query:"field" tags (logical and expected)
2. Backward compatibility: Still supports form:"field" tags (preserves existing code)
3. Mixed usage: Both tag types can be used in the same struct

type User struct {
    Name string `query:"name"`  // Now works! ✅
    Age  int    `form:"age"`    // Still works! ✅
}

// Using ShouldBindQuery() with ?name=John&age=30  
// Result: Name="John" Age=30 (both tags work)

Changes

• Modified queryBinding.Bind() to use new mapQuery() function instead of mapForm()
• Added mapQuery() function that calls mapFormByTag() for both "query" and "form" tags
• Added comprehensive test coverage for all scenarios
• Zero breaking changes - all existing code continues to work

Testing

func TestQueryBindingWithQueryTag(t *testing.T) {
    var s struct {
        Foo string `query:"foo"`
    }
    request := &http.Request{URL: &url.URL{RawQuery: "foo=HELLO"}}
    err := queryBinding{}.Bind(request, &s)
    assert.NoError(t, err)
    assert.Equal(t, "HELLO", s.Foo) // Now passes! ✅
}

All existing tests pass and test coverage remains at 99.2%.

Fixes #3235

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