set no of pv modules for MS800 GEN3PLUS inverters (#424)

* set no of pv modules for MS800 GEN3PLUS inverters

* fix unit test

* increase test coverage

* change the PV module handling

- in default we set the number of modules now to
  two. So with the first data from the inverter
  we only register two modules. After we determine
  the inverter module, the number can increase to
  four and more PV modules will be registered.

  With the default value of 4, we register always
  4 modules and can't reduce the number of areas
  when we detect that the inverter only supoorts
  two PV modules

app/tests/test_infos_g3p.py

@@ -109,7 +109,7 @@ def test_default_db():
     i = InfosG3P(client_mode=False)
     
     assert json.dumps(i.db) == json.dumps({
-        "inverter": {"Manufacturer": "TSUN", "Equipment_Model": "TSOL-MSxx00", "No_Inputs": 4}, 
+        "inverter": {"Manufacturer": "TSUN", "Equipment_Model": "TSOL-MSxx00", "No_Inputs": 2}, 
         "collector": {"Chip_Type": "IGEN TECH"},
         })
 
@@ -271,7 +271,7 @@ def test_build_ha_conf1():
         elif id == 'inv_count_456':
             assert False
 
-    assert tests==7
+    assert tests==5
 
 def test_build_ha_conf2():
     i = InfosG3P(client_mode=False)
@@ -346,7 +346,7 @@ def test_build_ha_conf3():
         elif id == 'inv_count_456':
             assert False
 
-    assert tests==7
+    assert tests==5
 
 def test_build_ha_conf4():
     i = InfosG3P(client_mode=True)