Move APIs into a central location

[sbueringer]

I think it would be great if our APIs would be in a central directory. Similar to https://github.com/kubernetes/kubernetes/tree/master/staging/src/k8s.io/api

Notes:

• Why?
  • Easier to find our APIs when they are in a central location. Currently that's a non-trivial exercise for our users
  • It enables us to introduce a separate api go module (this is not part of the current issue though)
• Why now? We are currently introducing v1beta2, folks will have to change their import paths anyway
• This does not include CAPD as it is not intended for production usage

The new structure would look roughly like this:

Additional tasks:

• Also align internal/apis folder

[sbueringer]

/cc @enxebre @JoelSpeed @vincepri @fabriziopandini @chrischdi

I'll also bring it up in the office hours today

[sbueringer]

/assign

[chrischdi]

/triage accepted

[nrb]

I'm a big +1 for this - though I can find what I need with rg, I often find myself looking in api then realizing what I wanted is somewhere like bootstrap or controlplane.