Minimum viable deserialization

Added TaskTemplate type
Added dummy data with (probably) usable format
Used the java.time classes instead of the legacy util.Date

src/main/java/module-info.java

@@ -2,7 +2,7 @@ module ch.zhaw.gartenverwaltung {
     requires javafx.controls;
     requires javafx.fxml;
     requires com.fasterxml.jackson.databind;
-
+    requires com.fasterxml.jackson.datatype.jsr310;
 
     opens ch.zhaw.gartenverwaltung to javafx.fxml;
     opens ch.zhaw.gartenverwaltung.types to com.fasterxml.jackson.databind;