Moved new v1 api into a fastapi sub application.

nomad/app/main.py

nomad/app/v1/__init__.py

nomad/app/v1/common.py

nomad/app/v1/main.py

nomad/app/v1/models.py

nomad/app/v1/routers/__init__.py

nomad/app/v1/routers/auth.py

nomad/app/v1/routers/datasets.py

nomad/app/v1/routers/entries.py

nomad/app/v1/routers/users.py

nomad/app/v1/utils.py

nomad/search.py

tests/app/conftest.py

tests/app/v1/__init__.py

tests/app/v1/conftest.py

tests/app/v1/routers/__init__.py

tests/app/v1/routers/common.py

tests/app/v1/routers/test_auth.py

tests/app/v1/routers/test_datasets.py

tests/app/v1/routers/test_entries.py