FIP-0118: editorial cleanup and missing sections

[rvagg]

This unfortunately pulls in all of #1270 because that comes from a fork and I want to add a commit on top of it that needs its own review. So when reviewing, please look at the head commit (only), the rest is the same as on #1270.

The intention here is to make this mergable in its current form. This change applies all of the non-controversial editorial and technical clean-ups that I highlighted in my review of #1270 and fills in a couple of the blank sections so it's ~complete. There's more updates to come based on the technical work, next for me would be changes coming out of the f02 design work which are not trivial changes but I'll keep them separate.

In this PR:

• Clarify reward-stream, weight, share and burn terminology ("weight" and "share" are both fractions but entirely separate, so the FIP should be clean on this)
• Correct stale statements, arithmetic, timing and section references.
• Tighten datacap deprecation and QAP transition wording.
• Narrow misleading consensus, security and governance claims.
• Add Backwards Compatibility and concrete Test Cases (a good-enough start, anyway, we'll update later).
• Replace the Implementation placeholder with current workstream links.
• Consolidate unresolved design and deployment work under TODO (this is a rough agent-generated list, but pretty good).
• Update the quarterly timeline from TWAP to fee-auction pricing.

#1270 didn't have any editor reviews, this is going to need 2 explicit ones on top of my implicit one to land. When we have that, I'll squash down @irenegia's commits to one and then we'll have a base to iterate on in this repo.

[rvagg]

latest tweak just adds code formatting to elements that deserve it, and a little bit more line wrapping treatment for consistency, no material changes

[dannyob]

Some minor language suggestions/typos. LGTM!

[jsoares]

Many TODOs, obviously -- and a pending stacked PR -- but this is in great shape for the stage.