Move error information out of printing/logging and into exception messages

[MetRonnie]

Describe exactly what you would like to see in an upcoming release

Example:

$ cylc clean running_workflow
WARNING - Cannot clean running workflow Mist.
    workflow contact file exists: ...
    blah blah...
    
CylcError: Clean failed: Mist

The problem with this is it's very CLI-centric and so if you try to clean a running workflow from the GUI you only get an alert saying "Clean failed: Mist" with no further context

Optimistically tagged against 8.1.1 but can be bumped

[oliver-sanders]

Partially addressed by #5359

[MetRonnie]

Here is an example UIS log snippet - need to figure out how to condense the relevant error messages down and include the final exception:

[I 2025-04-28 11:13:59.024 CylcUIServer] Cleaning ~ronnie.dutta/Simple
[I 2025-04-28 11:13:59.056 cylc] Cleaning Simple on install target: borked
[E 2025-04-28 11:13:59.334 cylc] Could not clean Simple on install target: borked
    platform: borked - clean up did not complete
    COMMAND:
        ssh -oBatchMode=yes -oConnectTimeout=10 bogus env \ 
    
            CYLC_VERSION=8.4.2 CYLC_ENV_NAME=cylc-8.4.2-1 bash --login \ 
    
            -c 'exec "$0" "$@"' timeout 600 cylc clean --local-only \ 
    
            --no-scan Simple --rm .service:log
    RETURN CODE:
        255
    STDOUT:
    STDERR:
        ssh: Could not resolve hostname bogus: Name or service not known
    
[E 2025-04-28 11:13:59.335 cylc] Failed to clean Simple
    Error: Remote clean failed for Simple
[E 2025-04-28 11:13:59.342 CylcUIServer] CylcError: Clean failed
    concurrent.futures.process._RemoteTraceback: 
    """
    Traceback (most recent call last):
      File ".../python3.9/concurrent/futures/process.py", line 246, in _process_worker
        r = call_item.fn(*call_item.args, **call_item.kwargs)
      File ".../python3.9/site-packages/cylc/uiserver/resolvers.py", line 202, in _clean
        return loop.run_until_complete(
      File ".../python3.9/asyncio/base_events.py", line 647, in run_until_complete
        return future.result()
      File ".../python3.9/site-packages/cylc/flow/scripts/clean.py", line 240, in run
        raise CylcError("Clean failed")
    cylc.flow.exceptions.CylcError: Clean failed
    """
    
    The above exception was the direct cause of the following exception:
    
    Traceback (most recent call last):
      File ".../python3.9/site-packages/cylc/uiserver/resolvers.py", line 250, in clean
        await asyncio.get_event_loop().run_in_executor(
    cylc.flow.exceptions.CylcError: Clean failed