FIR: Rework FirRegularTowerDataContexts

- Get rid of SPECIAL mode (just left REGULAR and class-related instead)
- Clear naming
- Restore contexts after lambda/callable reference are processed

The test has been failing before this change because after
callable reference is resolved, its tower data context has been left
erroneously in the SPECIAL-related entry

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -7170,6 +7170,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/dataFlow/IsExpression.kt");
             }
 
+            @Test
+            @TestMetadata("smartCastWithLambdaAndCallableReference.kt")
+            public void testSmartCastWithLambdaAndCallableReference() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/dataFlow/smartCastWithLambdaAndCallableReference.kt");
+            }
+
             @Test
             @TestMetadata("WhenSubject.kt")
             public void testWhenSubject() throws Exception {