Refactor: extract.IntoStructPtr should allow passing non-structure recipients

[outcatcher]

Currently there are some cases where returning result can be simplified in case IntoStructPtr allows passing non-structure recipients, e.g. *string.

Before:

	var res struct {
		ID string `json:"scaling_group_id"`
	}
	err = extract.Into(raw.Body, &res)

After:

 	var id string
	err = extract.IntoStructPtr(raw.Body, &id, "scaling_group_id")

In some built-in libraries (e.g. sql) there is no difference between structure and non-structure recipients: https://pkg.go.dev/database/sql#Rows.Scan

On the other hand, this function is called IntoStructPtr, not IntoPtr or IntoAnyPtr, so current function list to be discussed.

[Aloento]

agree