OrderedMap: Fix skipping elements while iterating with deletion

[RamanaReddy0M]

• closes: Bug: Skipping the elements while iterating with deletion operation #351

Code can be updated with this snippest:

func main() {
	om := mapsutil.NewOrderedMap[string, string]()
	om.Set("offset", "0")
	om.Set("limit", "10")
	om.Set("sort", "desc")
	om.Set("cwe-id", "CWE-77")

	ignoreKeys := []string{"offset", "limit", "sort"}

	om.Iterate(func(key string, value string) bool {
		fmt.Println(key, value)
		for _, ignoreKey := range ignoreKeys {
			if key == ignoreKey {
				om.MarkDelete(key)
				break
			}
		}
		return true
	})
	om.PruneDeleted()
}

[tarunKoyalwar]

minor updated, instead of marking delete outside we use dirty byte internally to track state when iterating