Use u32 for party & candidate numbers

[michielp1807]

As mentioned in #982, currently there cannot be more than 255 parties in Abacus because a u8 is used to store the party number. In the OpenAPI specification the pg_number is listed as int32, likely because OpenAPI does not have smaller integer types by default. The same thing also holds for the candidate numbers.

While it is unlikely there will be more than 255 parties in the Netherlands any time soon, using u8's is in my opinion unnecessarily restrictive. The couple of bytes saved by using u8s will in many cases remain empty anyways due to memory alignment.

[codecov]

Codecov Report

Attention: Patch coverage is 93.75000% with 1 line in your changes missing coverage. Please review.

Project coverage is 89.77%. Comparing base (87cb37c) to head (c15460b).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
backend/src/apportionment/mod.rs	66.66%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #985   +/-   ##
=======================================
  Coverage   89.76%   89.77%           
=======================================
  Files         248      248           
  Lines       12987    12995    +8     
  Branches     1318     1318           
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+ Hits        11658    11666    +8     
  Misses       1235     1235           
  Partials       94       94           

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[praseodym]

Thanks, lgtm! What do you think about adding a type alias type PGNumber = u32; (or similarly named)?

[michielp1807]

Thanks, lgtm! What do you think about adding a type alias type PGNumber = u32; (or similarly named)?

Good suggestion! I've updated the PR to use type aliases PGNumber and CandidateNumber

[Lionqueen94]

Could you run npm run gen:openapi in the frontend folder to make sure the openapi.ts is also updated :)

[michielp1807]

Could you run npm run gen:openapi in the frontend folder to make sure the openapi.ts is also updated :)

Thanks for the reminder! Turns out I was missing #[schema(value_type = u32)] in a few places, which caused a u32 type to be introduced in the OpenAPI specification. Now it correctly uses numbers, which means the TypeScript types can remain the same.