Move System::jsonExit to BaseModule->jsonExit

- This will ensure headers set in BaseModule->run will be carried in jsonExit scenarios
- Deprecate jsonExit() method in Core\System

src/Module/Item/Activity.php

@@ -89,6 +89,6 @@ class Activity extends BaseModule
 			'state' => 1,
 		];
 
-		System::jsonExit($return);
+		$this->jsonExit($return);
 	}
 }

src/Module/Item/Follow.php

@@ -71,6 +71,6 @@ class Follow extends BaseModule
 			'state' => 1
 		];
 
-		System::jsonExit($return);
+		$this->jsonExit($return);
 	}
 }

src/Module/Item/Ignore.php

@@ -82,6 +82,6 @@ class Ignore extends BaseModule
 			'state'   => $ignored,
 		];
 
-		System::jsonExit($return);
+		$this->jsonExit($return);
 	}
 }

src/Module/Item/Pin.php

@@ -84,6 +84,6 @@ class Pin extends BaseModule
 			'state'   => (int)$pinned,
 		];
 
-		System::jsonExit($return);
+		$this->jsonExit($return);
 	}
 }

src/Module/Item/Star.php

@@ -91,6 +91,6 @@ class Star extends BaseModule
 			'state'   => (int)$starred,
 		];
 
-		System::jsonExit($return);
+		$this->jsonExit($return);
 	}
 }