Locally funded channels

[Jasonvdb]

Fund channels locally from on chain wallet.
closes #30

Step 1: Create channel

const res = await lm.createChannel({
  counterPartyNodeId: 'abc123',
  channelValueSats: 20000,
  pushSats: 5000,
});

const { value_satoshis, output_script, temp_channel_id } = res.value;

Step 2: Create funding tx using on chain wallet (DO NOT BROADCAST)

• Convert output_script to address
• bitcoin-cli createrawtransaction '[{"txid":"<tx-id>","vout":<index>}]' '{"<address>":<btc>}'
• bitcoin-cli signrawtransactionwithwallet <raw-transaction-hex>

Step 2: Fund channel

const res = await ldk.fundChannel({
  temporaryChannelId,
  counterPartyNodeId: peers.lnd.pubKey,
  fundingTransaction: signedTx,
 });

[ovitrif]

@Jasonvdb @coreyphillips code looks ok by my judgement, I was eager to test it but it won't run the JS in the example app (android app starts, then shows red error screen)

was getting error:

Class private methods are not enabled. Please add @babel/plugin-proposal-private-methods to your configuration.

[ovitrif]

Added a PR with the changes I did, let's see if it also fixes e2e-android failing CI tests, as I was getting the same error:

• Fix Example app on Android for Local funded channels PR #269