Add Stdlib::Ensure::Package type

Like the ones for file, service.
Valid values taken from https://puppet.com/docs/puppet/7/types/package.html#package-attribute-ensure

Author: arjenz

spec/type_aliases/ensure_package_spec.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'Stdlib::Ensure::Package' do
+  describe 'valid handling' do
+    [
+      'present',
+      'absent',
+      'purged',
+      'disabled',
+      'installed',
+      'latest',
+      '1',
+      '1.1',
+    ].each do |value|
+      describe value.inspect do
+        it { is_expected.to allow_value(value) }
+      end
+    end
+  end
+  describe 'No complex types can match' do
+    context 'garbage inputs, no complex types can match' do
+      [
+        1,
+        1.1,
+        [1.1],
+        '',
+        { 'foo' => 'bar' },
+        {},
+      ].each do |value|
+        describe value.inspect do
+          it { is_expected.not_to allow_value(value) }
+        end
+      end
+    end
+  end
+end

types/ensure/package.pp

@@ -0,0 +1,2 @@
+# @summary Validate the value of the ensure parameter for a package
+type Stdlib::Ensure::Package = Variant[Enum['present', 'absent', 'purged', 'disabled', 'installed', 'latest'], String[1]]