[idea] Proposal: move *_rviz_plugin folders from common folder to a new folder like rviz_plugin

[felixf4xu]

Hi,

Currently, there are many *_rviz_plugin folders inside common folder. Some packages in common folder are really common since they are shared by several other packages, but the *_rviz_plugin packages are not. They are not shared by any other packages, so it's confusing to puth them inside common folder.

Since there are 20 packages name like *_rviz_plugin, I propose to move them into a newly created folder, for example, rviz_plugin, which is at the top level of this repo (same level as common folder now).

It's also an option to reuse the tools folder, since rviz plugins are used as tools.

[isamu-takagi]

https://github.com/orgs/autowarefoundation/discussions/4067
Thank you for the suggestion. We plan to split the tool repository in the above discussion. So I would appreciate it if you could join and share this proposal for the package structure.