[Test] Require specifying parser for FIR test. Unify names for FIR tests

Now all tests with `Fir` in name are named accordingly to parser which
  is used in them -- `FirPsi` or `FirLightTree`. This is needed to keep
  consistency between different types of tests, because there is no
  single default in parser mode between different scenarios of using FIR

plugins/kotlinx-serialization/tests-gen/org/jetbrains/kotlinx/serialization/runners/SerializationFirLightTreeAsmLikeInstructionsListingTestGenerated.java

@@ -19,7 +19,7 @@ import java.util.regex.Pattern;
 @SuppressWarnings("all")
 @TestMetadata("plugins/kotlinx-serialization/testData/codegen")
 @TestDataPath("$PROJECT_ROOT")
-public class SerializationFir2IrAsmLikeInstructionsListingTestGenerated extends AbstractSerializationFir2IrAsmLikeInstructionsListingTest {
+public class SerializationFirLightTreeAsmLikeInstructionsListingTestGenerated extends AbstractSerializationFirLightTreeAsmLikeInstructionsListingTest {
     @Test
     public void testAllFilesPresentInCodegen() throws Exception {
         KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("plugins/kotlinx-serialization/testData/codegen"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);

plugins/kotlinx-serialization/tests-gen/org/jetbrains/kotlinx/serialization/runners/SerializationFirLightTreeBlackBoxTestGenerated.java

@@ -17,7 +17,7 @@ import java.util.regex.Pattern;
 
 /** This class is generated by {@link org.jetbrains.kotlinx.serialization.TestGeneratorKt}. DO NOT MODIFY MANUALLY */
 @SuppressWarnings("all")
-public class SerializationFirBlackBoxTestGenerated extends AbstractSerializationFirBlackBoxTest {
+public class SerializationFirLightTreeBlackBoxTestGenerated extends AbstractSerializationFirLightTreeBlackBoxTest {
     @Nested
     @TestMetadata("plugins/kotlinx-serialization/testData/boxIr")
     @TestDataPath("$PROJECT_ROOT")

plugins/kotlinx-serialization/tests-gen/org/jetbrains/kotlinx/serialization/runners/SerializationFirPsiDiagnosticTestGenerated.java

@@ -16,7 +16,7 @@ import java.util.regex.Pattern;
 
 /** This class is generated by {@link org.jetbrains.kotlinx.serialization.TestGeneratorKt}. DO NOT MODIFY MANUALLY */
 @SuppressWarnings("all")
-public class SerializationFirDiagnosticTestGenerated extends AbstractSerializationFirDiagnosticTest {
+public class SerializationFirPsiDiagnosticTestGenerated extends AbstractSerializationFirPsiDiagnosticTest {
     @Nested
     @TestMetadata("plugins/kotlinx-serialization/testData/diagnostics")
     @TestDataPath("$PROJECT_ROOT")