feat(ios): lazy pager (iOS native side) (#332)

* feat(ios): lazy view renderer

* docs: remove unimplemented note (lazy pager is implemented)

* fix: unneeded renders when using initialPage without maxRenderWindow

* chore(ios): replace `self.` access with `_`

* fix(ios): initial page can fail correct layout on first render

Author: alpha0010

example/src/BasicPagerViewExample.tsx

@@ -26,9 +26,7 @@ export function BasicPagerViewExample() {
         onPageSelected={navigationPanel.onPageSelected}
         onPageScrollStateChanged={navigationPanel.onPageScrollStateChanged}
         pageMargin={10}
-        // Lib does not support dynamically orientation change
         orientation="horizontal"
-        // Lib does not support dynamically transitionStyle change
         transitionStyle="scroll"
         showPageIndicator={navigationPanel.dotsEnabled}
       >

ios/ReactNativePageView.h

@@ -7,27 +7,23 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface ReactNativePageView: UIView
 
-- (instancetype)initWithEventDispatcher:(RCTEventDispatcher *)eventDispatcher;
+- (instancetype)init;
 
-@property(nonatomic) NSInteger initialPage;
-@property(nonatomic) NSInteger lastReportedIndex;
-@property(nonatomic) NSInteger currentIndex;
+@property(nonatomic) NSInteger count;
+@property(nonatomic) NSInteger offset;
+@property(nonatomic) UIPageViewControllerNavigationOrientation orientation;
+@property(nonatomic) BOOL overdrag;
 @property(nonatomic) NSInteger pageMargin;
-@property(nonatomic, readonly) BOOL scrollEnabled;
-@property(nonatomic, readonly) BOOL showPageIndicator;
-@property(nonatomic, readonly) UIScrollViewKeyboardDismissMode dismissKeyboard;
+@property(nonatomic) BOOL scrollEnabled;
+@property(nonatomic) BOOL showPageIndicator;
 @property(nonatomic) UIPageViewControllerTransitionStyle transitionStyle;
-@property(nonatomic) UIPageViewControllerNavigationOrientation orientation;
+
 @property(nonatomic, copy) RCTDirectEventBlock onPageSelected;
 @property(nonatomic, copy) RCTDirectEventBlock onPageScroll;
 @property(nonatomic, copy) RCTDirectEventBlock onPageScrollStateChanged;
-@property(nonatomic) BOOL overdrag;
-
 
 - (void)goTo:(NSInteger)index animated:(BOOL)animated;
 - (void)shouldScroll:(BOOL)scrollEnabled;
-- (void)shouldShowPageIndicator:(BOOL)showPageIndicator;
-- (void)shouldDismissKeyboard:(NSString *)dismissKeyboard;
 
 @end