Import minimal lodash packages

[smhutch]

Summary

While I'm also bought into the larger goal of removing lodash completely, these changes are a halfway house towards that goal. With these changes, only used lodash modules should (I'm unsure how to verify this) end up in the eui bundle.

const throttle = require('lodash/throttle'), only the subset of lodash code your package uses will be bundled in projects that use your package.
Reference

Part of #360

Checklist

• Check against all themes for compatibility in both light and dark modes
• Checked in mobile
• Checked in Chrome, Safari, Edge, and Firefox
• Props have proper autodocs
• Added documentation
• Checked Code Sandbox works for the any docs examples
• Added or updated jest tests
• Checked for breaking changes and labeled appropriately
• Checked for accessibility including keyboard-only and screenreader modes
• A changelog entry exists and is marked appropriately

[kibanamachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[cchaos]

Jenkins, test this

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_4127/

[thompsongl]

Nice! We use this import method in most cases with lodash; thanks for finding these.

[chandlerprall]

Changes LGTM; Compared the full build locally, saves 70kb on the minified bundle. This savings would similarly propagate to downstream projects using es / lib builds if those projects do not otherwise import from lodash.