docs(sensing): update pointcloud type information

[drwnz]

Description

This PR updates the pointcloud type documentation to be consistent with recent changes in Autoware.
For background:
https://github.com/orgs/autowarefoundation/discussions/3533
https://github.com/orgs/autowarefoundation/discussions/3578

Related Autoware PRs:
autowarefoundation/autoware.universe#6996
autowarefoundation/sample_sensor_kit_launch#94

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[github-actions]

Documentation URL: https://autowarefoundation.github.io/autoware-documentation/pr-588/
Modified URLs:

• https://autowarefoundation.github.io/autoware-documentation/pr-588/design/autoware-architecture/sensing/data-types/point-cloud/