Work on integration tests

- add new entries for #70 and #74
- cleaned-up / enriched a little bit compute and exec tests

Signed-off-by: dubo-dubon-duponey <dubodubonduponey+github@pm.me>

examples/tests/compute/invalid/overload/new_def/main.cue

@@ -0,0 +1,16 @@
+package testing
+
+bar: #dagger: {
+
+	#new_def: "lala"
+
+	compute: [{
+		do:  "fetch-container"
+		ref: "busybox"
+	},
+		{
+			do: "exec"
+			args: ["true"]
+			dir: "/"
+		}]
+}

examples/tests/compute/invalid/overload/new_prop/main.cue

@@ -0,0 +1,16 @@
+package testing
+
+bar: #dagger: {
+
+	new_prop: "lala"
+
+	compute: [{
+		do:  "fetch-container"
+		ref: "busybox"
+	},
+		{
+			do: "exec"
+			args: ["true"]
+			dir: "/"
+		}]
+}