Easy code hosting integration setup

### Describe the problem

Once we have https://github.com/WeblateOrg/weblate/pull/19641, the project onboarding could be made simpler and more guided.

### Solution brainstorm

* After creating a project/workspace (either manually or via billing) user will be asked to connect it to the code hosting service
* After connecting, the code hosting-oriented component setup will be started

### Describe alternatives you have considered

_No response_

### Screenshots

_No response_

### Additional context

I've decided to omit this part from https://github.com/WeblateOrg/weblate/pull/19641 review feedback as this is a separate feature and that PR is already big enough to review.