Download collection as a zip

[mhsh312]

Fixes #273

Changes:

• Added a Download Collection button in the Share dropdown of Collection
• Added Download Collection in English translation file
• Added a new controller downloadCollection

Logic: I created a controller that makes a database call for a collection ID and then created a function formatCollection that changes the JSON format of this collection such that it becomes compatible with the existing addFileToZip function. I also handled the library file bundling with a new function bundleExternalLibsForCollection which makes it so each project gets it's own library file bundled.

End result: a zip file with the name of the collection and collection owner and all the projects of the collection as subfolders where each subfolder includes library files of that specific project.

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123

[raclim]

Thanks for working on this, this is really awesome! Looking over it at a glance I think this looks good so far. We're currently on break, so I'll try to give it a more thorough review once we come back early January!

[mhsh312]

Hey @raclim any updates on this?

[raclim]

I'm really sorry that it took a while to get back to this! I might've noted this on one of the other PRs you've submitted, but due to some of the changes here falling out of date and some of the other features/fixes we'd like to prioritize over the next two months, I'm going to close this pull request for now.

I'm really sorry again that it took a while to get to this and that we couldn't get this in at the moment, but please feel free to update and reopen this pull request in the future!