Use new API endpoints that support project-scoped Presets

[embik]

Note this requires all API endpoints in https://github.com/kubermatic/kubermatic/issues/7260 to be implemented.

What would you like to be added? / User Story:

For project-scoped Presets (aka "Credentials" in some parts of the code), we are going to provide new API endpoints for autocompletion (because they can be used with Presets) and interacting with presets. The full list of new APIs will be added to this issue once they are implemented.

We need to switch the dashboard to these new API endpoints so Presets assigned to a list of Projects can be used.