solana: Add missing test cases to test suite

[johnsaigle]

Cargo tests

• unregistered peer can't transfer
• can't transfer to unregistered peer
• can't transfer more than balance
• wrong inbox accounts
• paused contracts

example-native-token-transfers/solana/programs/example-native-token-transfers/tests/transfer.rs

Lines 48 to 53 in 82c8308

	// TODO: some more tests
	// - unregistered peer can't transfer
	// - can't transfer to unregistered peer
	// - can't transfer more than balance
	// - wrong inbox accounts
	// - paused contracts

Anchor

• Burn mode testing

example-native-token-transfers/solana/tests/example-native-token-transfer.ts

Lines 190 to 201 in 82c8308

	// describe('Burning', () => {
	// beforeEach(async () => {
	// await ntt.initialize({
	// payer,
	// owner,
	// chain: 'solana',
	// mint,
	// outboundLimit: new BN(1000000),
	// mode: 'burning'
	// })
	// });
	// });

• Quoter calculations and workflow (note the PR indicates that the program is untested) #274

• #278

• Test that TransferNotApproved error is returned when trying to redeem a transfer that has not been approved. This is a new error condition introduced by #336

[johnsaigle]

https://github.com/wormhole-foundation/example-native-token-transfers/pull/219/files should probably be merged before further work is done here, as it adds useful functions to help with testing