Update Camera.cpp to support color imaging for Ks21

[lagilfillan69]

While using the Ks21i with the current driver as it stands, I am trying to pull down the color images. The following color topics are published....

/multisense/left/image_color
/multisense/left/image_rect/color 

However, when you try to subscribe to either of these topics. The driver reports...
Camera: failed to start stream 0x44: Unsupported

I believe this is reflecting of earlier firmware versions of the Ks21i that could not support color. The code in line 353 - 358 in Camera.cpp

  supports_color_ = has_aux_camera_ ||
                      (system::DeviceInfo::HARDWARE_REV_MULTISENSE_KS21 != device_info_.hardwareRevision &&
                       system::DeviceInfo::HARDWARE_REV_MULTISENSE_ST21 != device_info_.hardwareRevision &&
                       system::DeviceInfo::HARDWARE_REV_MULTISENSE_REMOTE_HEAD_VPB != device_info_.hardwareRevision &&
                       system::DeviceInfo::HARDWARE_REV_MULTISENSE_REMOTE_HEAD_STEREO != device_info_.hardwareRevision &&
                       system::DeviceInfo::HARDWARE_REV_MULTISENSE_REMOTE_HEAD_MONOCAM != device_info_.hardwareRevision);

Also I know that the original ros driver was edited to fix the new labeling system of publishing these topics as aux color instead of the current format