THRIFT-5527: Don't swallow idl exceptions in Process function

Client: go

This allows ProcessorMiddlewares to access such exceptions, unless
there's a network error writing the response (which takes priority).

While I'm here, also make the indentation of Process function more
consistent, and make it consistent on returning false and an error when
the reading/writing fails.
diff --git a/lib/go/test/Makefile.am b/lib/go/test/Makefile.am
index 4b3ecda..2cca411 100644
--- a/lib/go/test/Makefile.am
+++ b/lib/go/test/Makefile.am
@@ -52,7 +52,8 @@
 				EqualsTest.thrift \
 				ConflictArgNamesTest.thrift \
 				ConstOptionalFieldImport.thrift \
-				ConstOptionalField.thrift
+				ConstOptionalField.thrift \
+				ProcessorMiddlewareTest.thrift
 	mkdir -p gopath/src
 	grep -v list.*map.*list.*map $(THRIFTTEST) | grep -v 'set<Insanity>' > ThriftTest.thrift
 	$(THRIFT) $(THRIFTARGS) -r IncludesTest.thrift
@@ -84,6 +85,7 @@
 	$(THRIFT) $(THRIFTARGS) EqualsTest.thrift
 	$(THRIFT) $(THRIFTARGS) ConflictArgNamesTest.thrift
 	$(THRIFT) $(THRIFTARGS) -r ConstOptionalField.thrift
+	$(THRIFT) $(THRIFTARGS) ProcessorMiddlewareTest.thrift
 	ln -nfs ../../tests gopath/src/tests
 	cp -r ./dontexportrwtest gopath/src
 	touch gopath
@@ -106,7 +108,8 @@
 				./gopath/src/servicestest/container_test-remote \
 				./gopath/src/duplicateimportstest \
 				./gopath/src/equalstest \
-				./gopath/src/conflictargnamestest
+				./gopath/src/conflictargnamestest \
+				./gopath/src/processormiddlewaretest
 	$(GO) test -mod=mod github.com/apache/thrift/lib/go/thrift
 	$(GO) test -mod=mod ./gopath/src/tests ./gopath/src/dontexportrwtest
 
@@ -145,6 +148,7 @@
 	NamesTest.thrift \
 	OnewayTest.thrift \
 	OptionalFieldsTest.thrift \
+	ProcessorMiddlewareTest.thrift \
 	RefAnnotationFieldsTest.thrift \
 	RequiredFieldTest.thrift \
 	ServicesTest.thrift \