Add action to pull auto generated docs from server

[Dr-Electron]

Is your feature request related to a problem? Please describe.

Currently we pull the SDK docs to build the API references. This is time consuming and not efficient as we pull on every build although the API references might not have changed. This will also happen for other API references which are not autogenerated yet, like for Identity or for the autogenerated config docs from app.go.

Describe the solution you'd like

The idea like it is described here https://github.com/iotaledger/devops/issues/377 would be to upload those files from the repos to a server so that the wiki can download them on build

Describe alternatives you've considered

It would also be possible to upload this files to the Releases, but that isn't really a nice solution imo

[Dr-Electron]

Waiting for the merge before we do this