DDS ROI support; enums in adapter

[maloel]

• dds sensor now extends to roi_sensor if an option exists that's named "Region of Interest"
  • this sensor directly translates set()/get() to this option
• add dds_rect_option, communicated as an array [x1,y1,x2,y2]
• add RS2_OPTION_REGION_OF_INTEREST, which is skipped by the Viewer
  • add a as_rect to union inside rs2_option_value
• add ROI support to dds-adapter

Tracked on [RSDEV-1904]

Also:

• move legacy set-option type conversion to rs-dds-option, as some options (e.g., error-polling) are set as floats from within librealsense
• guard against exceptions in options-changed callbacks
• add enum support to dds-adapter (enum values weren't transmitted before, so they weren't enums in the client)