Item14237: Changed extensions initialization order

Callbacks are to be registered first as they might be requested very
early unlike the tags which are needed much later when actual rendering
is carried out.

Added context 'extensionsInitialized'

core/lib/Foswiki/ExtManager.pm

@@ -440,18 +440,6 @@ sub loadExtensions {
 sub initialize {
     my $this = shift;
 
-    # Register macro tag handlers for enabled extensions.
-    foreach my $tag ( keys %{ $extTags{tags} } ) {
-        my $tagData = $extTags{tags}{$tag};
-        if ( $this->extEnabled( $tagData->{extension} ) ) {
-
-            # Store back mapping for later clean up.
-            push @{ $extTags{exts}{ $tagData->{extension} }{tags} }, $tag;
-            my $handler = $tagData->{class} // $tagData->{extension};
-            $this->app->macros->registerTagHandler( $tag, $handler );
-        }
-    }
-
     # Register callback handlers for enabled extensions.
     foreach my $cbName ( keys %extCallbacks ) {
         foreach my $cbInfo ( @{ $extCallbacks{$cbName} } ) {
@@ -466,6 +454,20 @@ sub initialize {
             $this->registerCallback( $cbName, \&_cbDispatch, $cbData );
         }
     }
+
+    # Register macro tag handlers for enabled extensions.
+    foreach my $tag ( keys %{ $extTags{tags} } ) {
+        my $tagData = $extTags{tags}{$tag};
+        if ( $this->extEnabled( $tagData->{extension} ) ) {
+
+            # Store back mapping for later clean up.
+            push @{ $extTags{exts}{ $tagData->{extension} }{tags} }, $tag;
+            my $handler = $tagData->{class} // $tagData->{extension};
+            $this->app->macros->registerTagHandler( $tag, $handler );
+        }
+    }
+
+    $this->app->enterContext('extensionsInitialized');
 }
 
 sub deregisterExtension {