Use apiFetch package for rest API calls

[wordpressfan]

Is your feature request related to a problem? Please describe.
When we do an ajax call, mostly we use the jquery ajax methods to do that and we already have a core package called api-fetch that we can use and get rid of those jquery ajax methods.

Describe the solution you'd like
I opened this issue to:

1. Mention all jquery ajax calls instances.
2. Evaluate this migration and how we can get benefit from.

Once we got those details, we can start grooming this by mentioning the exact steps and if we will do that once for all instances or we will just change some of them and delay the others when touched.

Describe alternatives you've considered
Based on the data mentioned above we will decide.

Additional context
An interesting finding from @remyperona about translation handling using this package and how it'd be beneficial.