[CHORE] Restructure and fix model mapping

.github/workflows/build_test_pip.yml

@@ -68,7 +68,7 @@ jobs:
       - name: Test with pytest
         run: |
           git clone https://github.com/gammapy/gammapy-data.git $GAMMAPY_DATA
-          pip install -e . 
+          pip install -e ".[tests]"
           pytest -vv --cov=gammapy_plugin --cov-report=xml --cov-report=term 
         env:
           NUMBA_DISABLE_JIT: 0
@@ -115,7 +115,7 @@ jobs:
       - name: Test with pytest
         run: |
           git clone https://github.com/gammapy/gammapy-data.git $GAMMAPY_DATA
-          pip install -e .
+          pip install -e ".[tests]"
           pytest -vv --cov=gammapy_plugin --cov-report=xml --cov-report=term 
         env:
           NUMBA_DISABLE_JIT: 0

gammapy_plugin/models/__init__.py

@@ -0,0 +1,8 @@
+from .spatial import PointSourceModelConverted, SpatialModelConverted
+from .spectral import SpectralModelConverted
+
+__all__ = [
+    "SpectralModelConverted",
+    "PointSourceModelConverted",
+    "SpatialModelConverted",
+]