use NSInteger for NS_ENUM instead of NSUInteger

Summary:
as title

in practice, this doesn't make any difference, but this is to follow the apple recommendation and for us to have a more consistent codebase.

https://developer.apple.com/library/content/releasenotes/ObjectiveC/ModernizationObjC/AdoptingModernObjective-C/AdoptingModernObjective-C.html

>The NS_ENUM macro helps define both the name and type of the enumeration, in this case named UITableViewCellStyle of type NSInteger. The type for enumerations should be NSInteger.
>Like enumerations, the NS_OPTIONS macro defines both a name and a type. However, the type for options should usually be NSUInteger.

Changelog: [Internal]

Reviewed By: sammy-SC

Differential Revision: D32641990

fbshipit-source-id: 56e4cd44cdefe54f61c90844665a685ee2d6ffad

Author: philIip

Libraries/Image/RCTImageLoaderProtocol.h

@@ -34,7 +34,7 @@ NS_ASSUME_NONNULL_BEGIN
  * Use PriorityPrefetch to prefetch images at a lower priority.
  * The priority logic is up to each @RCTImageLoaderProtocol implementation
  */
-typedef NS_ENUM(NSUInteger, RCTImageLoaderPriority) {
+typedef NS_ENUM(NSInteger, RCTImageLoaderPriority) {
   RCTImageLoaderPriorityImmediate,
   RCTImageLoaderPriorityPrefetch
 };

React/Base/RCTBridgeMethod.h

@@ -9,7 +9,7 @@
 
 @class RCTBridge;
 
-typedef NS_ENUM(NSUInteger, RCTFunctionType) {
+typedef NS_ENUM(NSInteger, RCTFunctionType) {
   RCTFunctionTypeNormal,
   RCTFunctionTypePromise,
   RCTFunctionTypeSync,

React/Base/RCTNullability.h

@@ -7,7 +7,7 @@
 
 #import <Foundation/Foundation.h>
 
-typedef NS_ENUM(NSUInteger, RCTNullability) {
+typedef NS_ENUM(NSInteger, RCTNullability) {
   RCTNullabilityUnspecified,
   RCTNullable,
   RCTNonnullable,

React/Base/RCTPerformanceLogger.h

@@ -8,7 +8,7 @@
 #import <Foundation/Foundation.h>
 
 // Keep this in sync with _labelsForTags
-typedef NS_ENUM(NSUInteger, RCTPLTag) {
+typedef NS_ENUM(NSInteger, RCTPLTag) {
   RCTPLScriptDownload = 0,
   RCTPLScriptExecution,
   RCTPLRAMBundleLoad,

React/CxxBridge/RCTCxxBridge.mm

@@ -76,7 +76,7 @@
 /**
  * Must be kept in sync with `MessageQueue.js`.
  */
-typedef NS_ENUM(NSUInteger, RCTBridgeFields) {
+typedef NS_ENUM(NSInteger, RCTBridgeFields) {
   RCTBridgeFieldRequestModuleIDs = 0,
   RCTBridgeFieldMethodIDs,
   RCTBridgeFieldParams,

packages/rn-tester/RCTTest/FBSnapshotTestCase/FBSnapshotTestController.m

@@ -208,7 +208,7 @@ - (BOOL)compareReferenceImage:(UIImage *)referenceImage toImage:(UIImage *)image
 
 #pragma mark - Private API
 
-typedef NS_ENUM(NSUInteger, FBTestSnapshotFileNameType) {
+typedef NS_ENUM(NSInteger, FBTestSnapshotFileNameType) {
   FBTestSnapshotFileNameTypeReference,
   FBTestSnapshotFileNameTypeFailedReference,
   FBTestSnapshotFileNameTypeFailedTest,