Node-red-node-twitter retweet support

[baruchiro]

Fixes #834

• [ ] Bugfix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)

Proposed changes

See #834. The retweet endpoint is different from the update endpoint, and I added it to the output node.

Checklist

• [x] I have read the contribution guidelines
• [ ] For non-bugfix PRs, I have discussed this change on the forum/slack team:
  No answers in the forum, but we discussed on #834.
• [x] I have run grunt to verify the unit tests pass
• [ ] I have added suitable unit tests to cover the new/changed functionality:
  Unfortunately, there are no tests for Twitter Nodes.

[linux-foundation-easycla[bot]]

The committers are authorized under a signed CLA.

• :white_check_mark: Baruch Odem (Rothkoff) (21f31cf4a04941d4e719497c4745266dabb72a7f)