added direction, justifyContent, and alignItems props on EuiFlexItem

[anishagg17]

Summary

Fixes : #1888

Checklist

• Check against all themes for compatibility in both light and dark modes
• Checked in mobile
• Checked in IE11 and Firefox
• Props have proper autodocs
• Added documentation 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]

We have mostly delayed work on issue #1888 because there may be implications with the implementation that need to be discussed hence the discussion label has not been removed from that issue. I'll mark this PR as discussion as well and as a team we will make a decision whether we should proceed with this solution or not. Thanks!

[snide]

We discussed this one as a team and decided to close out this PR and the related issue as unnecessary. We're a little worried this could cause a little too much downstream variance and make it harder to support.

Apologies. This was an older issue we hadn't thought on much till this brought it back from slumber.