Improvement on FE axios requests

[jrwbabylonlab]

The current implementation of the client to server call can be improved in a few areas: (i.e apiWrapper.ts)

1. Use single axios instance: move the initialisation of the axios to the top of the file OR have dedicated class and put it inside constructor.
2. No process.env.NEXT_PUBLIC_API_URL read for each method invocation.
3. Remove any types in the input parameters.