Fix pull-down menus of MQTT configuration node

[kazuhitoyokoi]

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

Proposed changes

In this pull request, I modified pull-down menus in the configuration node of the MQTT node. Currently, the retain fields are not selected as the default. And typedInput menus do not support internationalization.

By this pull request, I fixed these issues.

Checklist

• I have read the contribution guidelines
• For non-bugfix PRs, I have discussed this change on the forum/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 remained the same at 68.328% when pulling f872e2a on kazuhitoyokoi:master-fixmqttproperty into f060309 on node-red:master.

[kazuhitoyokoi]

Thank you.