plugins/kpackage: Rename metadata json files

Having them this long and the cpp file very short doesn't really make sense.

Also, we no longer install those files, but embed then in the C++ plugins

src/plugins/kpackage/aurorae/aurorae.cpp

@@ -43,6 +43,6 @@ public:
     }
 };
 
-K_PLUGIN_CLASS_WITH_JSON(AuroraePackage, "kwin-packagestructure-aurorae.json")
+K_PLUGIN_CLASS_WITH_JSON(AuroraePackage, "aurorae.json")
 
 #include "aurorae.moc"

src/plugins/kpackage/decoration/decoration.cpp

@@ -41,6 +41,6 @@ public:
     }
 };
 
-K_PLUGIN_CLASS_WITH_JSON(DecorationPackage, "kwin-packagestructure-decoration.json")
+K_PLUGIN_CLASS_WITH_JSON(DecorationPackage, "decoration.json")
 
 #include "decoration.moc"

src/plugins/kpackage/effect/effect.cpp

@@ -43,6 +43,6 @@ public:
     }
 };
 
-K_PLUGIN_CLASS_WITH_JSON(EffectPackageStructure, "kwin-packagestructure-effect.json")
+K_PLUGIN_CLASS_WITH_JSON(EffectPackageStructure, "effect.json")
 
 #include "effect.moc"

src/plugins/kpackage/scripts/scripts.cpp

@@ -41,6 +41,6 @@ public:
     }
 };
 
-K_PLUGIN_CLASS_WITH_JSON(ScriptsPackage, "kwin-packagestructure-scripts.json")
+K_PLUGIN_CLASS_WITH_JSON(ScriptsPackage, "scripts.json")
 
 #include "scripts.moc"

src/plugins/kpackage/windowswitcher/windowswitcher.cpp

@@ -41,6 +41,6 @@ public:
     }
 };
 
-K_PLUGIN_CLASS_WITH_JSON(SwitcherPackage, "kwin-packagestructure-windowswitcher.json")
+K_PLUGIN_CLASS_WITH_JSON(SwitcherPackage, "windowswitcher.json")
 
 #include "windowswitcher.moc"