Add methods to example

[finessevanes]

Currently the example: https://react-app.walletconnect.com/ only had the following methods to test:

• personal sign
• send transaction

Add:

• Sign typed data
• Sign transaction
• Send raw transaction

[bkrem]

These methods are all still available, but the logic in the sample dapp now properly excludes them from the session if the wallet didn't approve them, since all except personal_sign and eth_sendTransaction are proposed as optional.

See e.g. Rainbow in the screenshot below which does approve the optionals.

I've added a follow-up issue #220 to make this clearer in the UI, closing in favour of that.

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