service/vi: Improve OpenDisplay validation

Updates the OpenDisplay function in IApplicationDisplayService to properly
validate display names. Instead of only accepting "Default", now validates
against all known valid display names: "Default", "External", "Edid",
"Internal", and "Null".

- Changes log level from WARNING to DEBUG since this is no longer stubbed
- Adds proper validation for all valid display names
- Returns ResultOperationFailed for invalid display names
- Improves logging by including the requested display name

src/core/hle/service/vi/application_display_service.cpp

@@ -85,11 +85,25 @@ Result IApplicationDisplayService::GetIndirectDisplayTransactionService(
 }
 
 Result IApplicationDisplayService::OpenDisplay(Out<u64> out_display_id, DisplayName display_name) {
-    LOG_WARNING(Service_VI, "(STUBBED) called");
+    LOG_DEBUG(Service_VI, "called with display_name={}", display_name.data());
 
+    // Ensure the display name is null-terminated
     display_name[display_name.size() - 1] = '\0';
-    ASSERT_MSG(strcmp(display_name.data(), "Default") == 0,
-               "Non-default displays aren't supported yet");
+
+    // According to switchbrew, only "Default", "External", "Edid", "Internal" and "Null" are valid
+    const std::array<std::string_view, 5> valid_names = {
+        "Default", "External", "Edid", "Internal", "Null"
+    };
+
+    bool valid_name = false;
+    for (const auto& name : valid_names) {
+        if (name == display_name.data()) {
+            valid_name = true;
+            break;
+        }
+    }
+
+    R_UNLESS(valid_name, ResultOperationFailed);
 
     R_RETURN(m_container->OpenDisplay(out_display_id, display_name));
 }