Change the way how the Custom Tab works in the Coordinator Page

[frinzekt]

Currently the way how it works is that the custom tab is a component that conditionally exposes component. The problem with this is that it makes it very hard to navigate around the coordinator pages using links.

An example that makes it hard has arised from #64, wherein once a coordinator wants to go back, the link to go back is always the index, when ideally the coordinator should be taken to the review coordinator page.

What work needs to be done:

• modification of the custom tab
• custom hook (for loading data in the different pages). This should be similar to how the reviewer pages are done, wherein the custom hooks checks if the currently being viewed is updated by checking the courseID in the state and the URL. Calling only the server if the courseID is different or null