added a message on library card onnullcontent

[simaopsbarbosa]

Closes #1559
added a message to the library card onNullContent instead of the loading circle

testing it

to force the widget to show ONC, temporarily change the hasContent to:
hasContent: (libraryOccupation) => false,

Review checklist

• Terms and conditions reflect the current change
• Contains enough appropriate tests
• If aimed at production, writes a new summary in whatsnew/whatsnew-pt-PT
• Properly adds an entry in changelog.md with the change
• If PR includes UI updates/additions, its description has screenshots
• Behavior is as expected
• Clean, well-structured code

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.

Project coverage is 9%. Comparing base (df6be03) to head (dc198dd).
Report is 5 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff           @@
##           develop   #1576   +/-   ##
=======================================
- Coverage        9%      9%   -0%     
=======================================
  Files          261     261           
  Lines         7483    7488    +5     
=======================================
  Hits           650     650           
- Misses        6833    6838    +5     

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[DGoiana]

Can you add a screenshot of the final result? And can you maybe try to implement it with the new IconLabel? Just find an icon that you think it'll suit well.

[DGoiana]

🚀 🚀

[peucastro]

Looking great! Just for consistency, please align the text style with the one used in the onNullContent implementation from this PR #1529

[peucastro]

🚀✅