Create a GET route for for getting submission from the backend

[salaun-marion]

We need to create a GET route which provide to us this JSON answer:

{
"id": integer,
"title": string,
"abstract": string,
"authors":[
{
"firstname": string,
"lastname": string,
"email": string,
"affiliation": string,
"country": string,
"orcid": string,
"competing_interest": string
}
]
}

Figma link : https://www.figma.com/board/KZicqW9u9Ibj83DD3abLWu/Submission-improvement?node-id=0-1&p=f&t=E0PqwF1oo4vm0yt2-0