Ab#92198 add loading indicators

[MwanPygmay]

Description

• add loading indicators when resource/reference data is loading from widgets settings
• add loading indicator when tinymce is loading
• add loading indicator when monaco editor loading

Useful links

• Please insert link to ticket

Type of change

Please delete options that are not relevant.

• [x] Improvement (refactor or addition to existing functionality)

How Has This Been Tested?

Went in diverse components and checked that a loader appeared.

Screenshots

Checklist:

( * == Mandatory )

• [x] * I have set myself as assignee of the pull request
• [x] * My code follows the style guidelines of this project
• [x] * Linting does not generate new warnings
• [x] * I have performed a self-review of my own code
• [x] * I have put the ticket for review, adding the oort-frontend team to the list of reviewers
• [x] * I have commented my code, particularly in hard-to-understand areas
• [x] * I have put JSDoc comment in all required places
• [x] * My changes generate no new warnings
• [x] * I have included screenshots describing my changes if relevant
• [ ] * I have selected labels in the Pull Request, according to the changes with code brings
• [ ] I have made corresponding changes to the documentation ( if required )
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules

More explanation

https://www.loom.com/share/05a716d61b9744faaf51fb304c21d1e5?sid=f87cf896-582a-4f76-93ae-8ceed801b145