Description of problem:

For day 2, Cluster Details -> Machine Pool tab -> "Edit cluster autoscaling settings".
when user goes over 249 max nodes and hit the Save button the backend API and an error is returned in it's response.  As the screen recorder shows, the returned error message is not displayed to the user in the UI.  The backend error message should be displayed in the open dialog.

Note: other permutation exist which the backend verifies, thus we should display any/all backend error messages to the end user while they are in the dialog.

See the recordings in OCMUI-2713

How reproducible:
always

Steps to Reproduce:

1. Open OCM UI staging 
2. Open a ROSA classic wizard flow.
3. Fill all required fields from each wizard steps and reach to "Default machine pool" step.
4. Check " Enable autoscaling"
5. Click "Edit cluster autoscaling settings".
6. Change the max node total value to a -ve number.
7. See the validation.
8. Change the max node total value less than minimum node count requirement for the cluster autoscaling.
9. See the validation.
10. Close the wizard.
11. Go to cluster list and open a ready cluster.
12. Go to machine pool tab and click "Edit cluster autoscaling settings".
13. Repeat the step 6 and click "Save" button.
14. See the behavior
15. Repeat the step 8 and click "Save" button.
16. See the behavior

Actual results:

At step 7 & 9, there is no validation error thrown in OCM UI against max node total. However; the wizard submission blocked with backend error.
At step 14, As part of day 2 action, there is no validation error thrown in OCM UI against max node total.
Both Step 14 and 15,  The save action seems to indicate that data is saved successfully as there is no error in UI. But the backend request to update the autoscaling settings eventually failed. 

Expected results:

To avoid all above situation, introduce the validation for max node count field for below circumstances
1. At step 7 & 14,  Introduce the validation error in case of -ve value.
2. At step 9, Probably this is difficult for now and same complication discussed in OCMUI-2646  . We could ignore this behavior now.
3. At step 14 & 15 (day 2 actions), Throw an error in OCM UI while saving invalid or unsupported max node count total definition (i.e. when the  backend calls to update the autoscaling definition fails).