Split up core in smaller sub modules (#821)

* mv MathExpression

* mv SpatialSeries

* mv GenericSeries, SeriesParam

* mv TimeSeries

* added MathematicalExpression to __all__, sorted lines

* use abs imports in core module (e.g. from weldx import MathematicalExpression broke)

actually this is very strange, as the relative import triggers a behaviour to use relative import all over the place.

The weldx.util.util pkg imports an attr from asdf, but this import would be tried to resolve by Python (3.10) to the weldx internal "asdf" package.

* patch mod of "core" pkg

weldx/__init__.py

@@ -180,19 +180,25 @@
 
 __all__ = (
     "ArcSegment",
+    "Config",
     "CoordinateSystemManager",
-    "Geometry",
-    "GmawProcess",
     "DynamicBaseSegment",
     "DynamicShapeSegment",
+    "DynamicTraceSegment",
+    "Geometry",
+    "GmawProcess",
     "LineSegment",
+    "LinearHorizontalTraceSegment",
     "LocalCoordinateSystem",
+    "MathematicalExpression",
     "Profile",
     "Q_",
-    "U_",
     "Shape",
     "SpatialData",
+    "Time",
+    "TimeSeries",
     "Trace",
+    "U_",
     "WeldxFile",
     "asdf",
     "core",
@@ -202,11 +208,6 @@
     "transformations",
     "util",
     "welding",
-    "TimeSeries",
-    "DynamicTraceSegment",
-    "LinearHorizontalTraceSegment",
-    "Config",
-    "Time",
 )
 
 weldx.config.Config.load_installed_standards()

weldx/core/__init__.py

@@ -0,0 +1,14 @@
+"""Collection of common classes and functions."""
+# isort:skip_file
+from weldx.core.math_expression import MathematicalExpression
+from weldx.core.generic_series import GenericSeries
+from weldx.core.spatial_series import SpatialSeries
+from weldx.core.time_series import TimeSeries
+
+__all__ = ["MathematicalExpression", "GenericSeries", "SpatialSeries", "TimeSeries"]
+
+
+from ..util import _patch_mod_all  # noqa
+
+_patch_mod_all("weldx.core")
+del _patch_mod_all