Fixes #1867 - Color picker feature

[ameybh]

Fix #1867

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

Demo:

Features:

• Shows a color picker option when RGB or hex values are used.
• metaKey+K shortcut to popup color picker anywhere in the editor.

Issues:

• The tiny color view square doesn't update when colors are changed. This might be because of incompatibility between colorpicker-codemirror and this project. The colorview updates perfectly on simple example demos.

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• p5.js-web-editor
  • app-ted9947-p5-js-web-editor.releaseapp.io
  • preview-ted9947-p5-js-web-editor.releaseapp.io

🔧Environment Status : https://app.releasehub.com/public/Processing%20Foundation/env-5550122a5a