Fix apache::vhost::error_documents data type

The template in templates/vhost/_error_document.erb is only functionnal
if we pass an array of hashes.  This is going to be simplified in a
future commit so only accept values that produce working configuration
and reject configuration that is invalid and ignored.

manifests/vhost.pp

@@ -1798,7 +1798,7 @@
   Optional[Variant[String, Boolean]] $modsec_audit_log                                = undef,
   Optional[String] $modsec_audit_log_file                                             = undef,
   Optional[String] $modsec_audit_log_pipe                                             = undef,
-  Variant[Array[Hash], String] $error_documents                                       = [],
+  Array[Apache::Errordocument] $error_documents                                       = [],
   Optional[Variant[Stdlib::Absolutepath, Enum['disabled']]] $fallbackresource         = undef,
   Optional[String] $scriptalias                                                       = undef,
   Optional[Integer] $limitreqfieldsize                                                = undef,

spec/defines/vhost_spec.rb

@@ -340,7 +340,12 @@
               'error_log_file' => 'httpd_error_log',
               'error_log_syslog' => true,
               'error_log_format' => ['[%t] [%l] %7F: %E: [client\ %a] %M% ,\ referer\ %{Referer}i'],
-              'error_documents' => 'true',
+              'error_documents' => [
+                {
+                  'error_code' => '500',
+                  'document' => '/server-error.html',
+                },
+              ],
               'fallbackresource' => '/index.php',
               'scriptalias' => '/usr/lib/cgi-bin',
               'limitreqfieldsize' => 8190,

types/errordocument.pp

@@ -0,0 +1,5 @@
+# @summary A mapping for an error code and a document
+type Apache::Errordocument = Struct[
+  error_code => Variant[String[3, 3], Integer[400, 599]],
+  document   => String[1],
+]