Improvements in the Configuration page

As mentioned in autosubmit#1412, there is a good opportunity to improve the visualization of the configuration page.

Nowadays, this page just shows the latest run and the current filesystem configuration of the experiment. The main improvement will be to add a dropdown to select a run or the current filesystem configuration. More or less like this:

This change will need an additional change to the endpoint in the API since the current one just returns the two configs that are shown now.

Additionally, an improvement could be made to the way the settings are shown to be more readable.