Experiment module: improve the layout of Experiment entities

[aislinnpearson]

To make the layout between experiments, designs and plans a bit clearer it would be great it we could improve the layout of the experiment entities.

There are several elements to this.

@paul121 suggested we improve the way we use white boxes to layout related bits of information (see comment here. We do this to some extent with the Studies/ Plans, but could still be a bit more intuitive:

In addition, it would be nice to include the related entities on the landing page. Again this is something we already do for some entities (see experiment example below) but it could be tidier and more user friendly, with a specific focus on making it more intuitive how the different elements fit together. As a quick aside, we would not replace the 'Related' button (which we will rename 'Quick Links', see #672) but instead offer both options - with the emphasis on making it intuitive how the different elements fit together.