Fix navigation error when clicking active pipeline tab
What does this MR do and why?
Fix navigation error when clicking active pipeline tab
When the page first loaded the activeTabName value was null as we are trying to fetch the default value from validPipelineTabNames which doesn't include pipelineTabName as the pipeline tab is the root URL.
To fix this I've added a check to see if the current path is '' and then returned pipelineTabName.
I've also modified navigateTo to check if the clicked tab is already active.