play_storage_get UI & api doesn't scale well, needs pagination

[iturgeon]

Ideally, the api would only load what it needs to, loading paginated logs, 1000 at a time, per each semester.

Right now play_storage_get loads every single storage log in one call.

We'd probably need a new play_storage_summary_get api that would contain information about how many logs we have and what semesters they are in.

Then, when displaying a semester's data table, load them in, paginated, on demand.

Related: Storage table download works differently then the data export feature - right now the data export generates csvs on the server. Storage table downloads generate csvs on the client (possible because it loads all the data)