Fixed actions crashing on post history - Admin X (#18344)

refs https://ghost.slack.com/archives/C0568LN2CGJ/p1695642553045059

- this attempts to fix an undefined error on AdminX when accessing
history log.
- At the moment I only have it reproducible on staging, so if this doesn't fix it, it will potentially be reverted.

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### <samp>🤖 Generated by Copilot at 818fa49</samp>

Improve context handling for action events in `actions.ts`. Use a
variable to simplify and customize the action name and title based on
the context.

apps/admin-x-settings/src/api/actions.ts

@@ -182,23 +182,23 @@ export const getActionTitle = (action: Action) => {
         resourceType = 'tier';
     }
 
-    // Because a `page` and `post` both use the same model, we store the
-    // actual type in the context, so let's check if that exists
-    if (resourceType === 'post') {
-        if (action.context?.type) {
-            resourceType = action.context?.type as string;
+    const contextExists = action.context !== null;
+
+    if (resourceType === 'post' && contextExists) {
+        if (action.context.type) {
+            resourceType = action.context.type as string;
         }
     }
 
     let actionName = action.event;
 
-    if (action.event === 'edited') {
+    if (action.event === 'edited' && contextExists) {
         if (action.context.action_name) {
             actionName = action.context.action_name as string;
         }
     }
 
-    if (action.context.count && (action.context.count as number) > 1) {
+    if (contextExists && action.context.count && (action.context.count as number) > 1) {
         return `${action.context.count} ${resourceType}s ${actionName}`;
     }