fix(ios): initial render foreignObject / re-render on mount of sub views

ios/Elements/RNSVGForeignObject.h

@@ -1,9 +1,11 @@
 
 #import "RNSVGGroup.h"
 #import "RNSVGLength.h"
+#import "RCTEventDispatcher.h"
 
 @interface RNSVGForeignObject : RNSVGGroup
 
+- (instancetype)initWithEventDispatcher:(RCTEventDispatcher *)eventDispatcher;
 @property (nonatomic, strong) RNSVGLength *x;
 @property (nonatomic, strong) RNSVGLength *y;
 @property (nonatomic, strong) RNSVGLength *foreignObjectwidth;

ios/Elements/RNSVGForeignObject.m

@@ -7,19 +7,45 @@
  */
 #import "RNSVGForeignObject.h"
 #import "RNSVGNode.h"
+#import "RCTUIManager.h"
+#import "RCTUIManagerObserverCoordinator.h"
 
 @implementation RNSVGForeignObject
+{
+    RCTEventDispatcher *_eventDispatcher;
+    bool _ready;
+}
 
 - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
 {
     return nil;
 }
 
+- (instancetype)initWithEventDispatcher:(RCTEventDispatcher *)eventDispatcher
+{
+  RCTAssertParam(eventDispatcher);
+
+    if ((self = [super init])) {
+        _eventDispatcher = eventDispatcher;
+        [_eventDispatcher.bridge.uiManager.observerCoordinator addObserver:self];
+    }
+    return self;
+}
+
 - (void)parseReference
 {
     self.dirty = false;
 }
 
+- (void)uiManagerDidPerformMounting:(RCTUIManager *)manager
+{
+  [manager addUIBlock:^(__unused RCTUIManager *uiManager, __unused NSDictionary<NSNumber *, UIView *> *viewRegistry) {
+      if (!self->_ready && !self.dirty) {
+          [self invalidate];
+      }
+  }];
+}
+
 - (void)renderLayerTo:(CGContextRef)context rect:(CGRect)rect
 {
     [self clip:context];

ios/ViewManagers/RNSVGForeignObjectManager.m

@@ -15,7 +15,7 @@ RCT_EXPORT_MODULE()
 
 - (RNSVGForeignObject *)node
 {
-    return [RNSVGForeignObject new];
+    return [[RNSVGForeignObject alloc] initWithEventDispatcher:self.bridge.eventDispatcher];
 }
 
 RCT_EXPORT_VIEW_PROPERTY(x, RNSVGLength*)