Update dependencies

Closes none

What does this MR do?

Updates outdated dependencies.

How confident are you it won't break things if deployed?

Seem to work. I try to test as many cases as possible.

Links to related issues

None yet.

How to test

Chat

Updated chat dependencies:

• tape (run yarn test and check if everything works)
• eslint-plugin-node, eslint-plugin-import (check if there are any errors for linting)

Client

Updated client dependencies:

• @babel/core, @babel/preset-env, eslint-plugin-import, eslint-plugin-node, eslint-plugin-vue, vue-eslint-parser (if it builds, and it works without errors on the frontend/client there is not really a way to test it. I guess it'll tell you)
• core-js (this is kind of part of babel as far as I understand. I think that we could remove it. And here as well, no way to test it.)
• node-sass, underscore, css-loader, sass-loader, webpack (also no way to test it except for broken builds)
• css-loader and file-loader (mainly nodejs updates, when it builds, it works)
• jsdom and node-localstorage (node-localstorage is used by our jsdom setup file. jsdom can be tested by running yarn test)

Downgraded client dependencies:

• bootstrap-vue (check tooltips like the navigation bar on the top on the desktop and on mobile. Also check tooltips for the baskets as well. They should behave as they currently do in production, not like the faulty ones on beta)

Screenshots (if applicable)

None (yet)

Checklist

• added a test, or explain why one is not needed/possible...
• no unrelated changes
• asked someone for a code review
• joined #foodsharing-beta channel at https://slackin.yunity.org
• added an entry to CHANGELOG.md (description, merge request link, username(s))
• Once your MR has been merged, you are responsible to update the #foodsharing-beta Slack channel about what has been changed here. They will test your work in different browsers, roles or other settings

Todo

• update chat dependencies
• update client dependencies (except for the ones known to break
• revert tooltip changes (current behavior needs to be re-applied with newer versions of vue-bootstrap in a proper way)
• update backend dependencies