Add SponsorEverythingPaymaster

[jihoonsong]

What is this PR doing?

This PR adds SponsorEverythingPaymaster contract and its test, which can serve as references when developing more complex paymasters.

How can these changes be manually tested?

Its test is included in the existing plugin tests. i.e., run yarn hardhat test in packages/plugins will test the changes.

Does this PR resolve or contribute to any issues?

No.

Checklist

• I have manually tested these changes
• Post a link to the PR in the group chat

Guidelines

• If your PR is not ready, mark it as a draft
• The resolve conversation button is for reviewers, not authors
  • (But add a 'done' comment or similar)

[jacque006]

Overall solid starting example, thanks for the contribution 👍

[jacque006]

Minor suggestion

Suggested change

	await paymaster.deposit({ value: ethers.parseEther("1") })
	await paymaster.deposit({ value: oneEther })

Can also do this in a few other spots.

[jacque006]

Be explicit with return values here. Either:

Suggested change

	// Validation logic comes here.
	// Validation logic comes here.
	// Approve everything
	// validUntil & validAfter of 0 means infinite valid time range
	return ("", _packValidationData(false, 0, 0))

Or

        // Validation logic comes here.
        // Approve everything
        return ("", 0)