JetDiagnosticsTest migrated to TestGenerator

- test data files renamed from *.jet to *.kt

compiler/testData/diagnostics/tests/scopes/ImportTwoTimes.kt

@@ -0,0 +1,14 @@
+// FILE: a.jet
+
+package weatherForecast
+
+fun weatherToday() = "snow"
+
+// FILE: b.jet
+
+package myApp
+
+import weatherForecast.weatherToday
+import weatherForecast.weatherToday
+
+fun needUmbrella() = weatherToday() == "rain"