New "HomePage"

[ohager]

As the new version will get an entire Web UI, some preparations must be done for Jetty.

The proposed static HTML structure can be:

html
  - ui
    index.html
    favicon.ico
    ... all the react files of static build
  - api-doc (as is today)
  - dapps (new, local dapps aka static builds)
       - defi (signumswap)
       - phoenix
       - neo
       - sns
       - ...

As the new webui uses a modern stack based on ReactJS, most probably a toolchain needs to be established, similar to the one for /openapi, which has some unbundled source code and needs to be bundled/build.