replace payout status nomenclature with payout eligibility nomenclature

[gruns]

why? to improve clarity around payout eligibility and intimate that a node's payout eligibility is something that's earned, not a status that's applied to them. a node becomes 'elibible' for payouts once theyve satisfied their node's uptime requirement

to switch:

• [x] change Payout Status to Payout Eligibility
• [x] change status valid to Eligible
• [x] change status pending to In Progress (still not a huge fan of In Progress and thinking of a better word that connotes the node's eligibility is being earned, not just in progress)

eligibility, and nomenclature around eligibility over 'status', makes it clearer that nodes become qualify/become eligible for payouts

[AmeanAsad]

Adding an extra task here for myself:

• [ ] update uptime requirements documentation page after the edits (https://docs.saturn.tech/nodes-uptime-requirement)

[gruns]

@AmeanAsad i just updated the docs on both the docs.saturn.tech and the l1 docs (in this repo) with a note about the forthcoming change come july 1st

both the l1 readme and docs.saturn.tech will need to be updated again on july 1st, changing 7 days to 14 days 👍