fix(editor): Add 'Stop execution' button to execution preview

[MiloradFilipovic]

This PR introduces a few visual changes to the preview for running executions:

1. Stop execution button
2. Execution timer in the executions sidebar (shows live timer for running executions),
3. New spinner icon

[ivov]

Found the following. No deep context so if any are intended, please disregard.

1. Stopping a running execution triggers two toasts: error for Problem in node ‘On clicking 'execute'‘ Workflow-Execution has been canceled! (non-auto-dismissing) and success for Execution stopped. Execution ID X (auto-dismissing). I would think only the success toast is enough.
2. Selecting a stopped execution from the executions view triggers Workflow-Execution has been canceled!. I would not expect to see this toast again when selecting an old execution.
3. Retrying a stopped execution triggers Retry unsuccessful every time. The workflow is a simple Manual Trigger and Wait so it should be able to retry.
4. Selecting a failed retry of a stopped execution triggers "Cannot read properties of undefined (reading 'node')"
5. Setting up a lengthy execution and switching to Executions view auto-selects the last already completed execution, but I would expect the running execution to be auto-selected.
6. Disabling nodes in Workflow view is broken, have not tested if coming from master. Edit: Disregard, this is on master.

[MiloradFilipovic]

@ivov I would say this is all expected. Here's the reasoning:

1., 2. and 4. These popups were discussed when implementing this feature and we decided to keep all messages from the old execution preview. I just now talked with Max and the agreement is to remove the Failed execution messages that appear and pile up when opening failed executions. Also we agreed to be conservative with removing popups so we don't remove anything useful. Deleting mentioned popup will already clear a lot of clutter so I'll do this in next commit.

3. I don't have much context on this, but retrying stopped executions hasn't been possible in previous versions also (just tested 0.198.2). Will ask around to see why is this but for now would leave it out of scope for this particular PR.

5. Executions tab always remembers the last selected execution, so that one will be automatically opened when switching to it (or the first one if it's opened for the first time or remembered execution is not longer available).

Let me know if this all seems reasonable.

[janober]

Got released with n8n@0.203.0