Refactor LifecycleEditor to make it work with htmx

Htmx imports external javascript sources introduced in htmx responses, but
the run order is not like normal web pages, and thus previously we got an
error:

    Uncaught TypeError: RT.NewLifecycleEditor is not a constructor

Besides, because of js class declaration, if lifecycleui-model.js is
imported multiple times, we would get:

    Identifier 'LifecycleModel' has already been declared

This commit makes the following changes to make it work with htmx:

* Merge LifecyleModel into the anonymous js class saved in RT.NewLifecycleEditor

Via js class expression instead of a standard class declaration, we don't
need to worry about the code being imported multiple times.

* Move editor initialization code from inline to util.js for consistency

* Initialize only when editor is available

lib/RT/Interface/Web/MenuBuilder.pm

@@ -1822,9 +1822,6 @@ sub _BuildAdminPageMenu {
                     $page->child(
                         basics     => title => loc('Modify'),
                         path       => "/Admin/Lifecycles/Modify.html?Type=" . $Type_uri . ";Name=" . $Name_uri,
-                        attributes => {
-                            'hx-boost' => 'false',
-                        },
                     );
                 }
                 $page->child( actions => title => loc('Actions'), path => "/Admin/Lifecycles/Actions.html?Type=" . $Type_uri . ";Name=" . $Name_uri );

share/html/Admin/Lifecycles/Modify.html

@@ -55,7 +55,6 @@
 </div>
 
 <script type="text/javascript" src="<%RT->Config->Get('WebPath')%>/static/js/d3.min.js"></script>
-<script type="text/javascript" src="<%RT->Config->Get('WebPath')%>/static/js/lifecycleui-model.js"></script>
 <script type="text/javascript" src="<%RT->Config->Get('WebPath')%>/static/js/lifecycleui-editor.js"></script>
 
 <form action="<%RT->Config->Get('WebPath')%>/Admin/Lifecycles/Modify.html" name="ModifyLifecycle" method="post" enctype="multipart/form-data" class="mx-auto max-width-xl">

share/html/Elements/Lifecycle/Graph

@@ -45,7 +45,7 @@
 %# those contributions and any derivatives thereof.
 %#
 %# END BPS TAGGED BLOCK }}}
-<div class="lifecycle-ui" id="lifecycle-<% $id %>">
+<div class="lifecycle-ui" id="lifecycle-<% $id %>" data-config="<% $Config %>" data-maps="<% $Maps %>" data-layout="<% $Layout || '' %>" >
   <div id="lifeycycle-ui-edit-node" class="lifeycycle-ui-edit-node collapse card card-body">
     <input type="hidden" name="id" />
     <div class="alert alert-warning invalid-name hidden"><&|/l&>Invalid name</&></div>
@@ -74,11 +74,6 @@
     </div>
   </div>
 
-  <script type="text/javascript">
-    jQuery(function () {
-        new RT.NewLifecycleEditor( document.getElementById('lifecycle-<% $id %>'), <% $Config |n %>, <% $Maps |n %> <% $Layout ? ", $Layout" : () |n %> );
-    });
-  </script>
   <div class="row">
     <div class="col-auto">
       <span class="current-value form-control">