Consider dropping/simplifying all "smart" code

[laughedelic]

• we have quite some "smart" code here that derives things related to projects/tasks/etc. based on types and all that, but we don't use it anywhere
• the problem that appeared in Update project #13 (comment) is actually made out of nothing, because it doesn't need any dependent types: the function is just concatenates S3 addresses
• if we eventually will stop using cosas (or reduce its usage), I suggest start dropping all this stuff or replacing with simpler code now

@eparejatobes WDYT?