…w in view hierarchy

make sure release function is defined for Android WebView react component (#3)

[iOS] support releasing native WebView without a ref to the React WebView (#4)

fix EXC_BAD_ACCESS error by removing WKWebView reference to RNCWebView

Support message passing to native webview without react tag (#6)

fix EXC_BAD_ACCESS during remount situations (#7)

There are some specific edge cases where a crash currently happens
1) Let's say RNCWebview A is mounted on the screen.
2) RNCWebview B starts to mount (while A is still mounted) with the same webview key
3) RNCWebview B removes the WKWebview from A and attaches it to itself
4) RNCWebview A starts to unmount, and upon unmounting tries to remove WKWebview A from itself. Since RNCWebview B already did this step from (3), this causes a crash.

Here we only remove the view if the currently "set" RNCWebview inside the shared dict (where we keep track of the active view for a key) is self

fix segfault with webview remount (#8)

* fix another segfault

* address comments

…bView in view hierarchy

* add support to reuse instance with webViewKey

* change up

* address comments related to layout params

* add nullability checks

* fix

* get full stack trace

* add secondary map

* rename to ifHasInternalWebView

* additional fixes

* fix

* fix boolean

[android] add messaging passing without a react tag (#12)

This PR adds messaging passing. This was much simpler to do than the iOS counter part. This is the analogue to the following PR: #6. I've followed the same test plan. The sample app was really nice to use when testing.

In the previous PR #11, I broke all native->react-native communication since events were being passed by the `InternalWebView` viewId not the `RNCWebView` viewId. This is now fixed.

[android] check source prop if changed (#14)

* [android] check source prop if changed

* detect if new source is null too

* message passing cleanup

- rename onMessage -> ReactNativeWebviewOnMessageWithWebViewKey (due to globally unique event names)
- add a small wrapper for listening to events
- rename `enableMessaging` to `messagingWithWebViewKeyEnabled`

* remove empty line

* fix spacing

* fix spacing p2

* additional cleanup

* update comments

* make this a bit safer

…WebView to RNCWebView