Add an option that allows users to switch use REFLECTIVITY to fill the intensity values instead of INTENSITY

[Samahu]

Is your feature request related to a problem? Please describe.
Historically the driver used the INTENSITY values to fill the point cloud intensity, however, using the REFLECTIVITY would be more appropriate since the values are calibrated. It also has a meaningful max. Checkout #408

Describe the solution you'd like
To preserve the current behavior for old instance we need to add an option that allows the users to choose between the current mode or used the REFLECTIVITY values instead when populating pt.intensity.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Targeted Platform (please complete the following information only if applicable, otherwise dot N/A):

• Ouster Sensor?ANY
• Ouster Firmware Version? ANY
• ROS version/distro? ANY, for ROS2 humble and later set REFLECTIVITY as the default
• Operating System? ANY
• Machine Architecture? ANY