Make secrets global and init on first use.

This allows all containers to use any secret declared anywhere
in their placeholders but they will not be generated and
written to the configuration until they are used.

Signed-off-by: Alan Savage <3028205+asavageiv@users.noreply.github.com>

php/src/ContainerDefinitionFetcher.php

@@ -239,9 +239,12 @@ readonly class ContainerDefinitionFetcher {
                 $internalPort = $entry['internal_port'];
             }
 
-            $secrets = [];
             if (isset($entry['secrets'])) {
-                $secrets = $entry['secrets'];
+                // All secrets are registered with the configuration when they 
+                // are discovered so they can be later generated at time-of-use.
+                foreach ($entry['secrets'] as $secret) {
+                    $this->configurationManager->RegisterSecret($secret);
+                }
             }
 
             $uiSecret = '';
@@ -320,7 +323,6 @@ readonly class ContainerDefinitionFetcher {
                 $volumes,
                 $variables,
                 $dependsOn,
-                $secrets,
                 $uiSecret,
                 $devices,
                 $enableNvidiaGpu,