updates syr to take dynamic values for bundles and resourceS

[dmikey]

Syr can now use dynamic paths for JS Bundles, as well as Dynamic paths for Resources on iOS.

How this works.

[[SyrRootView alloc] initWithBundlePath:filePath initialProperties:appProps withResourceBundlePath:pyplBundlePath];

initWithBundlePath now works as expected. the path passed to this will be loaded.

withResourceBundlePath is new, provide a bundle resource path where assets/images should be loaded. It is still on component authors, to ensure they are looking for resources.

Authors should do a fall through like so

// check main bundle/xcassets for an image to load
 image = [UIImage imageNamed:source];
// no image loaded, check resourceBundlePath 
 if(image == nil) {
   NSString* resourceBundlePath = [[[SyrRaster sharedInstance] bridge] resourceBundlePath];
   NSBundle* bundle = [[NSBundle alloc] initWithPath:resourceBundlePath];
   image = [UIImage imageNamed:source inBundle:bundle compatibleWithTraitCollection:nil];
 }