SLAM-007: Configure Kitware SLAM Mapping Parameters

[lblommesteyn]

Summary

• add mapping_localization_python/config/slam_params_online.yaml with Kitware online mapping parameters and inline descriptions
• tune ICP registration behavior for ego-motion, localization, and loop closure
• configure map update cadence and map resolution settings for online mapping
• enable loop closure constraints and loop search parameters
• configure motion prediction defaults (ego_motion) and IMU prediction toggle
• update launch default to use slam_params_online.yaml
• update README default config path

Validation

• YAML parses successfully
• configured parameter keys match Kitware reference schema

[lblommesteyn]

Triage note from AP1 bringup: this looks like online Kitware SLAM parameter tuning, not required for the current RealSense bag smoke-test path. It is still potentially useful, but should probably get mapping/SLAM owner review before merging because it changes the default mapping params file.