[Hyperion] [FE] Namespace filter multiple issues fix on app list

[manish-agrawal-ai]

• Selecting one more cluster from the list is clearing out all selected namespaces from the filter
• If multiple clusters are selected & no namespaces are selected for any cluster and applied then it's clearing out the cluster from the filter
• Removing namespaces from the filter is clearing out the respective cluster when multiple clusters are selected

[sohel-rp]

Changes have been made and are under review.
Related PR: devtron-labs/dashboard#292.