Reduce CCN in json_utils.cpp (parameterLimitsToJson/FromJson) (#1085)

Summary:
Pull Request resolved: #1085

Refactored the `parameterLimitsToJson` and `parameterLimitsFromJson` functions to reduce their cyclomatic complexity (CCN) below the target of 20.

Changes made:
- Created per-type helper functions in an anonymous namespace for both serialization (toJson) and deserialization (fromJson) operations
- Added helper functions: `minMaxToJson`, `minMaxJointToJson`, `linearToJson`, `linearJointToJson`, `halfPlaneToJson`, `ellipsoidToJson` for serialization
- Added helper functions: `parseJointParameterIndex`, `minMaxFromJson`, `minMaxJointFromJson`, `linearFromJson`, `linearJointFromJson`, `halfPlaneFromJson`, `ellipsoidFromJson` for deserialization
- The main `parameterLimitsToJson` and `parameterLimitsFromJson` functions now act as simple dispatchers calling the appropriate helper functions
- Combined `MinMaxJoint` and `MinMaxJointPassive` handling using a shared helper with a type parameter
- Combined `ellipsoid` and deprecated `elipsoid` (typo) handling using shared helper with key parameters
- Preserved all existing comments, including the TODO for deprecated `elipsoid` type migration

Reviewed By: cdtwigg

Differential Revision: D95214692

fbshipit-source-id: 085397d11385d7d5a90a601e4d0a268d0803ed67

Author: cstollmeta