Move scripts used in CI to the new location (#1109)

* Move CI scripts to new location

* Update references

* Update CODEOWNERS file

* Update docker/polkadot-collator_builder.Containerfile

Co-authored-by: Alexander Samusev <41779041+alvicsam@users.noreply.github.com>

Co-authored-by: Alexander Samusev <41779041+alvicsam@users.noreply.github.com>

scripts/ci/changelog/test/test_basic.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require_relative '../lib/changelog'
+require 'test/unit'
+
+class TestChangelog < Test::Unit::TestCase
+  def test_get_dep_ref_polkadot
+    c = SubRef.new('paritytech/polkadot')
+    ref = '13c2695'
+    package = 'sc-cli'
+    result = c.get_dependency_reference(ref, package)
+    assert_equal('7db0768a85dc36a3f2a44d042b32f3715c00a90d', result)
+  end
+
+  def test_get_dep_ref_invalid_ref
+    c = SubRef.new('paritytech/polkadot')
+    ref = '9999999'
+    package = 'sc-cli'
+    assert_raise do
+      c.get_dependency_reference(ref, package)
+    end
+  end
+end