Resolve #60 "Add proper checks for the sizes of Submission files"

Closes #60 (closed)

Notes:

Most changes have been made in core-fe and core-be for correcting the max upload sizes. Core-fe for being an order of magnitude off, and core-be to override the default value from Django.

Relies on associated core-fe PR: https://stgit.dcs.gla.ac.uk/team-project-h/2021/cs11/ybc-core-fe/-/merge_requests/25. No more change to core-be have to be added as they have already been added: https://stgit.dcs.gla.ac.uk/team-project-h/2021/csp4/yes_project_core_be/-/commit/ecf54af4e1d48458e68caa9e473f7d2266145a8b

Demo:

Screen_Recording_2022-03-16_at_14.09.56

Viewing took a while due to compute being slow :P

Manual Testing TBC:

• Check that files >1Mb can be uploaded
• Check that files >10Mb cannot be uploaded