Adding smart contracts, deploy script, and test files

[t-phoenix]

Smart Contract

• QuestFactory: factory to create New Quest and keep track of deployed Quests
• QuestDonation: Quest Contract keeps track of donation limit ($5000/year), and admin can allow ERC20 token donations, and must enable oracle contract for tokens.

For Native ETH: Use address(0) to allowToken and setPriceOracle

Script

• Deploy.s.sol: Deploy Contracts, Setup First Quest, and Interact by Donating and withdrawing funds.
• 1_DeployQuest: Deploys Quest factory and Quest Donation Contracts
• 2_SetupQuest: Admin allows ETH and USDC for valid donations, and add oracle price feeds for the same
• 3_InteractionQuest: Donate and Withdraw ETH/ USDC for sample function invokes

Test

• QuestDonation.t.sol: Basic Testing around QuestDonationContract.

[leinss]

Thanks for the PR.

There's the additional setup which has to happen somewhere, to allow tokens & set the price oracle.

That can go into the quest factory and be set once & read by each quest donation.

Would merge it though as is, and improve in next pr