To make it easier to understand senate elections, implement new election page designs

[noahmanger]

As part of the work to address 4 year presidential terms and 6 year senate terms, as well as address continuing confusion about the way that different senate classes are handled by the election search and election pages, create wireframes that address the proposed new behavior:

Election search:

• Show all offices currently relevant to that user, regardless of whether that office has an election in the next general election.
• If an office doesn't have an election in the current cycle, display the current officeholder but no link to an election page
• Always display both sitting senators, but only link to the page for the seat that is up for that election (if there is one)
• When searching past elections, the "Current officeholder" of each office should be the "Contemporary officeholder" (with a better name); i.e. whoever held that office in the cycle selected.

Election pages:

• Show contemporary officeholders and the election date for that given cycle
• Special elections should live at a url that ends in /special; e.g /elections/senate/ny/2013/special
• Senate election pages should display both classes for that state in the main info header at the top, with a link to the next or last election for the other seat
• Allow presidential pages to be viewed as their 4 year totals and senate pages to be viewed as their 6 year totals, but limited only to the relevant class
• Election year selecting should be consistent with the proposed year selecting interaction wireframed from this issue: Wireframe new cycle behavior #801

[noahmanger]

I've posted wireframes for two ways to handle the new senate election pages in InVision here: https://invis.io/RE4GG62GB

I drew up two different ways to handle Senate pages: A) Make separate pages for different Senate seats in a state; B) Include both seats on the same election page, but with further information about each one.

I include notes on the screens explaining the logic about what gets displayed where.

[noahmanger]

Related to this card: https://18f.storiesonboard.com/m/fec/!card/EO_Ee1HCYGbMMTnTx3CXqg