Migrate odometry display (#275)

* Move odometry display and covariance classes

* Make everything compile and fix linters

* Move covariance_visual to rviz_rendering

- covariance_property is no friend class anymore
- make covariance_visual independent of geometry_msgs

* Add to plugins_descriptions.xml file

* Minor refactoring of CovarianceProperty

* Remove Eigen dependency in rviz_default_plugins

* Add tests to odometry_display

* Move scene graph introspection to rviz_rendering

- Split scene_graph_introspection into gmock dependent/independent part
- add helpers methods to find rviz shapes
- polish methods to make them available throughout RViz

* Add rudimentary tests for CovarianceVisual

* Extract quaternion helper and include a test

* Add possibility to change arbitrary subproperties to testing framework

* Add visual test for odometry display

* Refactoring of CovarianceVisual

* Add further tests for odometry_display

* Refactoring of odometry_display.cpp

* Make covariances behave like other RViz objects

- The property is now only a container for GUI interaction
- Covariance visuals need to be kept in the display
- Allow simple setting of property content for every visual
- Make CovarianceVisual independent of rviz_rendering::Object since there is no relation anymore (not all objects derive from Object anyway)

* Set error status if tansform fails

* Fix tests after rebase

* Move odometry_display.hpp to include folder

* Fix tests after rebase

* Harmonize failed transfor error status

migration_guide.md

@@ -101,6 +101,9 @@ The following is an incomplete list of changes (to be expanded when porting more
 
 - `BillboardLine: newLine()` → `finishLine()` (identical functionality, but `finishLine()` can be called exactly `n` times, where `n` is the number of lines in the billboard line, whereas `newLine()` could only be called `n-1` times)
 - `PointCloud: addPoints(...)` now takes vector iterators as arguments instead of pointer and size.
+- `CovarianceVisual`: Does not inherit from `rviz_rendering::Object` anymore and has a much restricted interface.
+Previously, this was only used by `rviz_common::properties::CovarianceProperty`.
+To streamline interfaces, handling of visuals now needs to be done in the display: Set up a slot fetching data from the covariance property handing it over to CovarianceVisual (see OdometryDisplay for an example).
 
 ## rviz_common
 
@@ -114,3 +117,5 @@ For an example of how to do this, see PointCloudSelectionHandler.
 Then the function can be used for handler creation and the SelectionHandler works as previously.
 - In general, several functions within `SelectionManager` and `ViewPicker` have been moved to private API.
   If they are needed, please provide a pull request to the RViz repository explaining why this functionality is needed.
+- `CovarianceProperty`: Previously used CovarianceVisual, now contains only a number of properties.
+See `rviz_rendering::CovarianceVisual` for further information and OdometryDisplay in `rviz_default_plugins` for an example usage.