runtimerender: export QSSGEulerAngleConverter, and move related API inside it

Many of the functions found in QQuick3DNode belongs better in
QSSGEulerAngleConverter. By refactoring them inside that class, we
can also use them from other places, and in particular from
QQuick3DNode where we need to calculate the global matrix.
2 jobs for master in 3 minutes and 51 seconds
Status Job ID Name Coverage
  Build
failed #35338
linux
build_with_linux

00:01:51

failed #35339
windows
build_with_windows

00:03:51

 
Name Stage Failure
failed
build_with_windows Build
Generating Code...
Generating Code...
jom: C:\GitLab\builds\16AXKVHV\0\annichol\qtquick3d\build\src\quick3d\Makefile [debug-all] Error 2
jom: C:\GitLab\builds\16AXKVHV\0\annichol\qtquick3d\build\src\Makefile [sub-quick3d-make_first-ordered] Error 2
jom: C:\GitLab\builds\16AXKVHV\0\annichol\qtquick3d\build\Makefile [sub-src-make_first] Error 2
Running after script...
$ echo "Finished"
"Finished"
ERROR: Job failed: exit status 2
failed
build_with_linux Build
Makefile:267: recipe for target 'sub-quick3d-make_first-ordered' failed
make[1]: *** [sub-quick3d-make_first-ordered] Error 2
make[1]: Leaving directory '/home/qt/builds/jGY9z3-8/0/annichol/qtquick3d/build/src'
Makefile:49: recipe for target 'sub-src-make_first' failed
make: *** [sub-src-make_first] Error 2
Running after script...
$ echo "Finished"
Finished
ERROR: Job failed: exit status 1