Add error handling for null return from getServiceAccountName

[muzaffarmhd]

What should be cleaned up or changed?

in the handleLogin function on the login page, when the user is null or the service account name cannot be retrieved, the page reloads without handling this. This might need a change, maybe we could add a toast saying "failed to get service account name"

Why is this needed?

Adding a toast to inform the user about the failure would improve the UX by giving them a proper feedback instead of a silent reload.

[ghosind]

Hello, this error should be fixed by #49

[muzaffarmhd]

alright, my bad, I didn't check the PR, thanks