[#1766] Update p5.js to 1.2.0

[catarak]

Fixes #1766
I have verified that this pull request:

• has no linting errors (npm run lint)
• is from a uniquely-named feature branch and has been rebased on top of the latest develop branch. (If I was asked to make more changes, I have made sure to rebase onto develop then too)
• is descriptively named and links to an issue number, i.e. Fixes #123

[release-com]

Release Environments

p5.js-web-editor
app-ted0e4f-p5-js-web-editor.releaseapp.io