Refactor AgencyHomePage to be inline with HomePage

[LoneRifle]

AgencyHomePageWrapper breaks consistency with how HomePage is structured, since most of the layout is in AgencyHomePage, with the wrapper mostly adding a HomePageProvider around AgencyHomePage. This contrasts with HomePage, which has most of the layout as well as HomePageProvider in the same file.

Extract the hook-dependent components into a separate file, and merge the wrapper into AgencyHomePage.

Originally posted by @LoneRifle in #1594 (comment)