Support i18n in websocket node

[kazuhitoyokoi]

Types of changes

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

Proposed changes

I found that the status messages in websocket nodes are English. I fixed 22-websocket.js to support i18n.

Checklist

• I have read the contribution guidelines
• For non-bugfix PRs, I have discussed this change on the mailing list/slack team.
• I have run grunt to verify the unit tests pass
• I have added suitable unit tests to cover the new/changed functionality

[coveralls]

Coverage decreased (-0.05%) to 75.631% when pulling 0615444 on kazuhitoyokoi:master-fixwebsocketnode into 9d219c1 on node-red:master.

[kazuhitoyokoi]

@knolleary Thank you 👍