Merge pull request GeodynamicWorldBuilder#850 from MFraters/add_euler_pole_velocity_plugin

Add oceanic plate euler pole velocity plugins.

Author: MFraters

CHANGELOG.md

@@ -18,8 +18,9 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - There is now a properties_output_size function, which returns the size of the output vector/array returned by the properties functions for a given properties input vector \[Menno Fraters; 2024-10-27; [#765](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/765)\]
 - Added 2d and 3d versions of the properties function to the C wrapper \[Menno Fraters; 2024-10-27; [#765](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/765)\]
 - Added continental geotherm from Chapman (1986) for the Temperature Model in Continental Plate \[Alan Yu; 2025-01-21; [#778](https://github.com/GeodynamicWorldBuilder/WorldBuilder/issues/778), [#797](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/797)\]
-- Min and max depth parameters now have an the option to accept a string which can be used select a model. \[Menno Fraters; 2025-08-23 [#842](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/842)]
-- You can now add LITHO1.0 layers as the min depth or max depth in the continental plate, oceanic plate and mantle models. \[Menno Fraters; 2025-08-23 [#842](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/842)]
+- Min and max depth parameters now have an the option to accept a string which can be used select a model. \[Menno Fraters; 2025-08-23; [#842](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/842)\]
+- You can now add LITHO1.0 layers as the min depth or max depth in the continental plate, oceanic plate and mantle models. \[Menno Fraters; 2025-08-23; [#842](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/842)\]
+- Added a Euler pole velocity field (in spherical coordinates) for the continental plate, oceanic plate and mantel layer. \[Menno Fraters; 2025-08-25; [#850](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/850)\]
 
 ### Changed
 - The tian2019 composition model now returns a mass fraction instead of a mass percentage. \[Daniel Douglas; 2024-11-12; [#767](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/767)\]