Update all plugin metadata to specify API version

plugins/CuraEngineBackend/__init__.py

@@ -9,11 +9,11 @@ catalog = i18nCatalog("cura")
 
 def getMetaData():
     return {
-        "type": "backend",
         "plugin": {
             "name": "CuraEngine Backend",
             "author": "Ultimaker",
-            "description": catalog.i18nc("CuraEngine backend plugin description", "Provides the link to the CuraEngine slicing backend")
+            "description": catalog.i18nc("CuraEngine backend plugin description", "Provides the link to the CuraEngine slicing backend"),
+            "api": 2
         }
     }
 

plugins/GCodeWriter/__init__.py

@@ -8,7 +8,6 @@ catalog = i18nCatalog("cura")
 
 def getMetaData():
     return {
-        "type": "mesh_writer",
         "plugin": {
             "name": "GCode Writer",
             "author": "Ultimaker",

plugins/LayerView/__init__.py

@@ -9,12 +9,12 @@ catalog = i18nCatalog("cura")
 
 def getMetaData():
     return {
-        "type": "view",
         "plugin": {
             "name": "Layer View",
             "author": "Ultimaker",
             "version": "1.0",
-            "description": catalog.i18nc("Layer View plugin description", "Provides the Layer view.")
+            "description": catalog.i18nc("Layer View plugin description", "Provides the Layer view."),
+            "api": 2
         },
         "view": {
             "name": catalog.i18nc("Layers View mode", "Layers"),