Support generic map slice

[Nikita Boldasov]

Example:

package main

import "fmt"

type MapItem[K, V any] struct {
	Key   K
	Value V
}

type SpecificMapValue struct {
	Field1 string
	Field2 int
	Field3 bool
}

func main() {
	var mapSlice []MapItem[string, SpecificMapValue]
	// next we should do unmarshalling:
	// yaml.Unmarshal([]byte("some yaml here"), &mapSlice)
	// but generic map slices aren't supported yet
	fmt.Println(mapSlice)
}

[Nikita Boldasov]

Would it be enough to make MapItem an interface here?
Something like that:

type MapItem interface {
	KeyToAny() interface{}
	ValueToAny() interface{}
}

Then the generic MapSlice implementation would be out of go-yaml's scope.
E.g. the following code could be used in the app:

type MapSlice[K, V any] []MapItem[K, V]

type MapItem[K, V any] struct {
	Key   K
	Value V
}

func (m MapItem[K, V]) KeyToAny() interface{} {
	return m.Key
}

func (m MapItem[K, V]) ValueToAny() interface{} {
	return m.Value
}

Or the latter code could be on the go-yaml's side too.