Add Source creation/edition + Add missing edit forms for tasks and events

ui/windows/EditSourceWindow.slint

@@ -0,0 +1,47 @@
+import { Backend } from "../Backend.slint";
+import { VerticalBox, CheckBox } from "std-widgets.slint";
+import { SideBar } from "../components/SideBar.slint";
+import { VButton, VText, VTextInput, Palette } from "@selenite";
+
+export component EditSourceWindow inherits Window {
+	in-out property <int> id;
+	in-out property name <=> nameInput.text;
+	in-out property path <=> pathInput.text;
+
+	title: "Mirai - Edit source";
+	min-height: 100px;
+	max-height: 4000px; // needed, otherwise the window wants to fit the content (on Swaywm)
+	min-width: 400px;
+	default-font-size: 16px;
+	background: Palette.background;
+
+    VerticalLayout {
+		padding: 16px;
+		spacing: 8px;
+		nameInput := VTextInput {
+			label: "Name";
+		}
+		pathInput := VTextInput {
+			label: "Path";
+		}
+		VButton {
+			text: "Save";
+			clicked => { 
+				Backend.modify-source({
+					id: root.id,
+					name: nameInput.text,
+					path: pathInput.text
+		  		})
+			}
+		}
+		VButton {
+			text: "Delete";
+			background-color: Colors.red;
+			double-clicked => { 
+				Backend.delete-source(root.id)
+			}
+		}
+     }
+}
+
+export { Backend, Palette } // Export to make it visible to the C++ backend