Debugger: Prohibit 'suspend fun' calls in evaluated expressions

Currently, it's impossible to call suspend functions in evaluated code fragments (see KT-31701).
This commit officially prohibits such calls, so users will see a semi-friendly error message.

idea/testData/debugger/tinyApp/src/evaluate/singleBreakpoint/suspendCalls.kt

@@ -0,0 +1,11 @@
+package suspendCalls
+
+suspend fun main() {
+    //Breakpoint!
+    foo()
+}
+
+suspend fun foo(): Int = 42
+
+// EXPRESSION: foo()
+// RESULT: Evaluation of 'suspend' calls is not supported

idea/testData/debugger/tinyApp/src/evaluate/singleBreakpoint/suspendCalls.out

@@ -0,0 +1,7 @@
+LineBreakpoint created at suspendCalls.kt:5
+Run Java
+Connected to the target VM
+suspendCalls.kt:5
+Disconnected from the target VM
+
+Process finished with exit code 0