Refactor/doi endpoint - Githubissues

In this pull request, I've made a few changes:

Altered the author name to non-unique. If a duplicate name is added, the slug field now appends a suffix to ensure uniqueness.
Not saving the API Json to the database anymore. As we've choosen another endpoint, only the doi and citation are being stored.
Added scale field on the upload step 2 page.
Changed the position of My medias link in the navigation.
I added a button that directs the user to the specific reference of the citation.
The options to add taxon and location are now avaiable in My curations media page.

bruvellu / cifonauta