deprecation: remove proxysettings from owner specification

[oliverbaehler]

Describe the feature

We support ProxySettings on the OwnerSpec on the tenant. However we want to seperate the proxy more strictly therefor in this release we are going to drop proxySettings from any Capsule API and just using it on the proxysettings CR.

Discussed in #1003 (comment)

What would the new user story look like?

How would the new interaction with Capsule look like? E.g.

1. What are the prerequisites for this?
2. Tenant owner creates a new Namespace
3. This is going to be attached to the Tenant
4. All the magic happens in the background

Feel free to add a diagram if that helps explain things.

Expected behavior

A clear and concise description of what you expect to happen.