Update the DropDownModule to visualise actual drop downs

[chrislaupama]

At the moment our DropDownModule component displays the data as a list, we want to have our drop downs look more appealing and functional.

I've had a look at the library we are using (react-bootstrap) and they have some drop downs available: https://react-bootstrap.github.io/components/dropdowns/

Implement the drop downs so each dropdown represents a module, and within the dropdown list it contains the assessments for that module.

For each assessment, it would also be good to have the following:

• [x] Have each assessment link go to the evidence page passing through the assessment data as props
• [x] Have each assessment within the drop down display some sort of icon to quickly identify the progress (like a X a tick and a circle etc)

Note that there should be 4 module dropdowns for each of the modules