1. Move skyline-apiserver to libs
2. Modify Makefile
3. Rename the skyline-apiserver.yaml.sample file to skyline.yaml.sample
At the top level, we use "skyline" as the namespace, using the idea of
monorepo to manage the project. At the top level, only some common
configuration files (mypy.ini, black.conf, isort.conf, etc.) and
common tools are included.
In the `libs` directory, there are three core libraries,
skyline-console, skyline-apiserver, skyline-nginx, and some dependent
libraries.
There are cross-imports between these libraries,
for example: skyline-nginx requires skyline-apiserver;
Both skyline-nginx and skyline-apiserver require skyline-config.
Therefore, skyline-apiserver should not be placed
at the top level, it is also suitable for management as a library.
Change-Id: Ie2f1f4bdfbc2e985ec4327705eecaae3181f5b50