Added PhantomWallet class to simplify the interaction with Phantom Wa…

[jokumusic]

…llet.

This makes it easy for code reuse throughout an application or even creating an instance inside of a hook.
I've been using this in my react native expo app for the last month and it works well. I create an instance inside of a Context component and my entire application has access to interact with Phantom and get notified of changes(connects, disconnects, etc...)

[JupiterXiaoxiaoYu]

I have encountered an error: "failed to get recent blockhash: TypeError: Network request failed" using your version

Signing transaction...
Getting recent blockhash

failed to get recent blockhash: TypeError: Network request failed
at node_modules\@solana\web3.js\lib\index.browser.esm.js:null in Connection#getLatestBlockhash
at node_modules\@babel\runtime\helpers\asyncToGenerator.js:null in asyncGeneratorStep
at node_modules\@babel\runtime\helpers\asyncToGenerator.js:null in _throw
at node_modules\promise\setimmediate\core.js:null in tryCallOne
at node_modules\promise\setimmediate\core.js:null in setImmediate$argument_0
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:null in _allocateCallback$argument_0
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:null in _callTimer
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:null in _callReactNativeMicrotasksPass
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:null in callReactNativeMicrotasks
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:null in __callReactNativeMicrotasks
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:null in __guard$argument_0
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:null in __guard
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:null in flushedQueue

[Unhandled promise rejection: TypeError: undefined is not an object (evaluating '(yield connection.getLatestBlockhash().catch(function (err) {]
at App.tsx:null in Promise$argument_0
at node_modules\@babel\runtime\helpers\asyncToGenerator.js:null in asyncGeneratorStep
at node_modules\@babel\runtime\helpers\asyncToGenerator.js:null in _next
at node_modules\promise\setimmediate\core.js:null in tryCallOne
at node_modules\promise\setimmediate\core.js:null in setImmediate$argument_0
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:null in _allocateCallback$argument_0
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:null in _callTimer
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:null in _callReactNativeMicrotasksPass
at node_modules\react-native\Libraries\Core\Timers\JSTimers.js:null in callReactNativeMicrotasks
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:null in __callReactNativeMicrotasks
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:null in __guard$argument_0
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:null in __guard
at node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:null in flushedQueue