Add routing step to Input Setup Wizard

[grotlue]

Description

closes #20568
/jpd Graylog2/graylog-plugin-enterprise#9273
/nocl

This PR:

• Adds the new "Setup Routing" step which allows the selection of existing streams and shows a warning for connected pipelines
• Cleans up/moves unused components
• Removes some logic in the determineFirstStep method which is not needed this cycle, however, kept the method itself as logic will be added with more steps
• Added a stepHelper with helper functions for working with steps and data
• Some more small cleanup, mainly due to requirement changes
• Adds tests for the stepHelper, and feature tests for the wizard and the routing step

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

[ousmaneo]

I tested the wizard feature, and it overall looks good. I have a suggestion inline.

[ousmaneo]

We have a hook (useStreams) that provides streams, and we also have a global Streams context provider that provide the streams list. we could use it here.

const { data: streams, isLoading: isStreamsLoading } = useQuery<Array<Stream>>(['streamsMap'], StreamsActions.listStreams);

[grotlue]

Good point, will use the hook instead.

[ousmaneo]

LGTM