Modification of sensor data publisher

[Hiroaki-Masuzawa]

The following modifications have been changed.

• Skip the publishing process when there is no connection.
• Modified publishing data type according to format.
• Add CameraInfo publisher.

[ssr-yuki]

Thank you. Your suggestions are important.

However, this PR adds/affects multiple features while it includes only one commit. It is difficult for us to discuss, organize, and merge it, with this PR structure.

Could you open one PR for each topic?

• Skip the publishing process when there is no connection: looks nice for me.
• Add CameraInfo publisher: also nice.
• Modified publishing data type according to format: important, but more discussion needed.

Moreover, we are glad if you format your codes: Choreonoid recommends you to use the Camel case for all variables, use ++i instead of i++ for counters, avoid multiple operations on the same line, etc.

[Hiroaki-Masuzawa]

Thank you for your comment.

I will create 3 separate pull requests, but I created 2 (#12, #13) of them first because there are many conflicts between the pull requests.

I am not familiar enough with the coding standards, so I would appreciate your comments.