Add ApplicationData datatype

[yuanchen233]

As discussed in #484, introducing a new datatype to hold applicationDataand set default serializer to ApplicationDataSerializer. This way we don't need to specify the serializer used everytime we use applicationData.

Changes:

1. New type ApplicationData holds a String field data.
2. In ApplicationDataSerializer, a not null String value is expected for field data
3. All applicationData are now type of ApplicationData?
4. Update TypeScript wrapper

[Whathecode]

The changes look good!

However, I figured this should target main, so this fix is available prior to your other PR (which otherwise still has a bugged commit).

Or, you fix the other PR by adding the custom serializer on the String?, which then in this PR gets removed again. But, I tend to avoid that type of multiple modifications if better prerequisites are known. 🙂

I can rebase/move stuff for you if you want. Other than code style and commit order, I think these PRs are good to be merged.

[yuanchen233]

Sounds good.

I can rebase/move stuff for you if you want. Other than code style and commit order, I think these PRs are good to be merged.

Yes please, and thanks. I try to avoid doing interactive rebase here (at least for now), as there is a chance I mess up everything and creates more work for both of us. 🙂

[Whathecode]

I just rebased on develop and removed the use of ApplicationData in the commits which aren't yet merged to the develop branch.

I also slightly reworked the ApplicationData and ApplicationDataSerializer documentation to avoid redundancies. The type now already documents the purpose, so no real need to reiterate on that fully on the serializer.