Description of problem:
The Provider forms were not enforcing that credentials were valid prior to saving.

Version-Release number of selected component (if applicable):
5.6.0

Planned changes:
Results of a chat discussion seem to be that we should not allow Save button to enable until all required form fields are entered and all end point credentials have been validated. So:

* On each end point tab, if validation is needed, show the tab in red (or somehow indicate the tab needs attention) and display a red message inside the tab area stating "Validation required".

* If relevant form fields (i.e. IP, Host Name, Port, credentials, etc) are changed on the form, this invalidates any validations that have been done, the tabs turn red again with validation required message, and Save is disabled.

* Pressing Validate on an end point tab may take longer due to network/timeout issues, but at least this would be expected, rather than overloading Save to do the validation.

* Save is only enabled if all form fields are valid and all entered credentials have been validated, so pressing Save only has to save the record. Refresh workers should then be able to start successfully.