Describe the bug

Some components without any resources don't show any message.

To Reproduce

1. Sign in as admin
2. Create a new process
3. Create components without any resource
4. Go to the "Preview" page
5. See that some Resources show a message ("There are no proposals yet.") but others don't show anything.

Expected behavior

All the empty pages should show a message like "There are no proposals yet."

Screenshots

Stacktrace

No response

Extra data

• Decidim Version: v0.28.0.dev but it also applies to v0.27.0 and lower
• Decidim installation: Nightly

Additional context

I thought about this one while reviewing #11870

Components to be checked:

• Accountability - Show message when there are no contents in accountability  #12012 and Redesign: display alert when no projects #11480
• Blog - Show error message when there are no posts in blogs #12013
• Budgets - Show error message when there are no budgets nor projects in budgets #12034
• Debates - Show message when there are no debates #12037
• Elections - Do not show counters and filters when there isn't any election #12055
• Meetings - already implemented with Warn the user when not meetings or upcoming meetings scheduled. #995 😄
  
• Page - Show message when there are no content in the page #12056
• Proposals - already implement with Information message when there isn't any Proposal #6063 🚀
  
• Sortitions - Show message when there are no sortitions #12057
• Survey - Show message when there are no questions in survey #12065