Implemented some CityObjectElements and enabled tesselatE

Enabled tesselate. If you set tesselate is false, tessellation is skipped.
Implemented RectifiedGridCoverage.
Implemented ExternalReference.
Implemented Lod0Geometry
Implemented Loc0ImplicitRepresentation
Implemented Lod0TerrainIntersection
Implemented Lod0Network
Implemented Lod0MultiCurve
Implemented Lod0MultiSurface
Implemented GeneralizesTo

Thank you @HarutakaMatsumoto

What's Changed

• Implemented some CityObjectElements and enabled tesselate by @HarutakaMatsumoto in #62

Full Changelog: 2.3.0...2.4.0