Effects: add diagnostic tests on contracts

- Make AbstractDiagnosticsTest dump function contracts
- Add diagnostics tests on parsing contracts
- Add diagnostics tests on smartcats in presence of functions with
contracts
- Add diagnostics tests on initialization and flow in presence of
in-place called lambdas

==========
Introduction of EffectSystem: 16/18

compiler/testData/diagnostics/testsWithStdLib/contracts/controlflow/initialization/unknown/unknownInvocations.kt

@@ -0,0 +1,17 @@
+// !LANGUAGE: +CallsInPlaceEffect
+// !DIAGNOSTICS: -INVISIBLE_REFERENCE -INVISIBLE_MEMBER
+
+import kotlin.internal.contracts.*
+
+fun <T> inPlace(block: () -> T): T {
+    contract {
+        callsInPlace(block)
+    }
+    return block()
+}
+
+fun reassignmentAndNoInitializaiton() {
+    val x: Int
+    inPlace { <!VAL_REASSIGNMENT!>x<!> = 42 }
+    <!UNINITIALIZED_VARIABLE!>x<!>.inc()
+}

compiler/testData/diagnostics/testsWithStdLib/contracts/controlflow/initialization/unknown/unknownInvocations.txt

@@ -0,0 +1,6 @@
+package
+
+public fun </*0*/ T> inPlace(/*0*/ block: () -> T): T
+    CallsInPlace(block, UNKNOWN)
+
+public fun reassignmentAndNoInitializaiton(): kotlin.Unit