Restore old obisort and add LCA functionnality to obiannotate.

Former-commit-id: aecaacc9dae49f74bd888a8eb8140822d31a42a6

pkg/obiutils/slices.go

@@ -21,3 +21,16 @@ func LookFor[T comparable](arr []T, x T) int {
 func RemoveIndex[T comparable](s []T, index int) []T {
 	return append(s[:index], s[index+1:]...)
 }
+
+func Reverse[S ~[]E, E any](s S, inplace bool) S {
+	if !inplace {
+		c := make([]E,len(s))
+		copy(c,s)
+		s = c
+	}
+    for i, j := 0, len(s)-1; i < j; i, j = i+1, j-1 {
+        s[i], s[j] = s[j], s[i]
+    }
+
+	return s
+}