Bulk file upload

Description

Types of changes

[x] I have read the CONTRIBUTING doc
[x] I have checked that unit tests pass locally with my changes
[x] I have run the npm script lint on the frontend and backend
[x] I have added tests that prove my fix is effective or that my feature works
[x] I have added necessary documentation (if appropriate)
[x] I have approval from the product owner for the contribution in this pull request