Fix validator fields in get_validator_from_deposit

[jtraglia]

When comparing the spec to Teku, I noticed that (1) effective_balance was in the wrong spot and (2) slashed wasn't being set. There's no bug here, just fixing for correctness & to make reviewing easier.

consensus-specs/specs/phase0/beacon-chain.md

Lines 358 to 367 in a2e16c8

	class Validator(Container):
	pubkey: BLSPubkey
	withdrawal_credentials: Bytes32 # Commitment to pubkey for withdrawals
	effective_balance: Gwei # Balance at stake
	slashed: boolean
	# Status epochs
	activation_eligibility_epoch: Epoch # When criteria for activation were met
	activation_epoch: Epoch
	exit_epoch: Epoch
	withdrawable_epoch: Epoch # When validator can withdraw funds