Clarify Validator economics - receiving accounts for validator revenue receipts

Context

When a validator serves as committee member, they receive income from 4 sources:

Income stream	Receiving account	Distribution	Description
staking rewards	`treasury` account	epoch end	This is from their own self-bonded stake
commission revenue	`treasury` account	epoch end	This is commission on staking rewards for the total bonded stake bonded to the validator taken according to the validator's commission rate
priority fee tips	`validator identifier` account	block finalisation	When a block proposer, priority fees for transactions included in the block are transferred directly to the validator node address, the `validator identifier` account
slashing rewards	`treasury` account	epoch end	As the reporting validator of an accountable fault a validator may receive slashing rewards. The staking rewards for offending validator for the epoch are forfeited and become the slashing rewards sent to the reporting validator

It is currently covered in 2 places:

It should be clearly stated in https://docs.autonity.org/concepts/validator/#validator-economics. which accounts receive validator revenue.

Revise Validator economics.

[x] Replace the current bullet point list with the complete table of income sources per above
[x] Review content for clarify

Clarify block proposer rewards.

autonity / docs.autonity.org