ReviewRequestPageEntry used to be pretty independent from

ReviewRequestPageData, with each entry either taking specific objects

(like a HTTP request, review request, and other state) in the

constructor or in utility methods, and the build_entries function

bridging the data and entries. This was a nice separation, but over time

as the entry needed to do more it ended up resulting in a lot of state

having to be passed around and inconsistency in what data was available

on what entry. With some upcoming work, this only got worse. In the end,

this maybe wasn't a necessary separation to keep, since they're always

used together.
Entries are now passed the ReviewRequestPageData directly, giving them

direct access to the review request, HTTP request, and calculated state.

This simplifies function signatures, entry building, code paths, and

will allow upcoming changes to give entries more control over their own

state.

Unit tests pass.
Tested manually with a review request I have that tests all entry states.