browse: add endpoint to show snapshot by id

We're missing a browse endpoint that shows the content of a snapshot by id.

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Migrated from T974 (view on Phabricator)

added Web app priority:Wishlist labels

Unless I misunderstood, this is already implemented and deployed: https://archive.softwareheritage.org/api/1/snapshot/

changed title from API: add endpoint to show snapshot by id to browse: add endpoint to show snapshot by id

changed the description

API endpoint to display snapshot content is already implemented but not the browse one, so I am updating the task details

assigned to @anlambert

closed

mentioned in commit 947d0baf

reopened

added priority:Normal label and removed priority:Wishlist label

closed