Reviewing and updating major changes for data types regarding...

Reviewing and updating major changes for data types regarding Entity-Property-Relationship within the NGSI-LD OAS v1.8.1: 1) Generating new schemas for new data types: JsonProperty, ListProperty, and ListRelationship. 2) Updating the additionalProperties field within the schemas of Entity, Property, Relationship, and derives, and the referenced schemas within the AttributeFragment request body. 3) Updating the Relationship schema for considering new properties such as entity and objectType, and fixing the data type for object property. 4) Fixing minor issues: removing allOf wrapper from previousValue property of the Property schema and from value property of GeoProperty schema.