Executive memberships

[tmtmtmtm]

Display Executive-level memberships per Person, and per-Government, including pivoting to a view of who else has held that same position over time.

[tmtmtmtm]

Depends on everypolitician/everypolitician#178

[chrismytton]

Have done a prototype of this in #13600.

The prototype was useful as a guiding light, but I think for the next stage we probably want to throw that away and do a fresh version using TDD.

[chrismytton]

TODO

• Add classes to the lib/everypolitician_extensions.rb file for interacting with position data. Prototype of this in [WIP] Everypolitician::Positions prototype #15608.
  • Everypolitician::Position which represents an individual position held
  • Everypolitician::Positions for filtering and interacting with positions data
    • Should be able to filter by type (we just want to show the cabinet positions initially)
    • Should be able to filter by term, i.e. "give me all the positions between these two dates"
• Add Everypolitician::UnstablePositionCSV class for getting the position data out of the unstable/positions.csv file. Add a way to get cabinet membership data for a person #15606
  • This can then be replaced with another class when we decide where the position data will live.
• Allow Everypolitician::Popolo::Person instances to access the position data for the person

[tmtmtmtm]

superseded by everypolitician/everypolitician#651