fix: keep DVL water-mass layers within sensor ranges

[yeseorizi]

Problem

Four DVL descriptors set the water-mass far boundary to 100 m even though their declared maximum ranges are smaller. Gazebo rejects these tracking settings before the affected DVLs can publish data.

Fix

Use each descriptor's existing maximum range as the far boundary: 75, 81, 66 and 90 m for Nortek DVL1000-300, Teledyne Explorer1000, Explorer4000 and WHN, respectively. No sensor range or noise specification is increased. Add a pytest regression for the eight Gazebo DVL configurations and a catalog-presence check.

Validation

• Latest main (50f3a5e) with the new regression: 4 failed / 5 passed; failures identify exactly the four affected descriptors.
• Fixed branch: 9/9 passed; posim_sensor_models builds and its colcon tests pass on Linux ARM64 / ROS 2 Lyrical.
• In the earlier integrated release-gate run, all eight configured DVLs published payloads and shut down. That run also included other local fixes; it is not a standalone cross-platform test of this PR.

Run after building the package:

colcon test --merge-install --packages-select posim_sensor_models
colcon test-result --verbose

This corrects invalid configuration, not physical DVL accuracy. Other architectures remain for CI/reviewer validation.