Remove FareComponent

[leonardehrenfried]

FareComponent is a representation of a fare price being valid for several legs. It has however, been superseded by FareProducts and explicit mappings to legs. Unfortunately we have now 2 representations that are similar but subtly incompatible. Keeping them in sync is very complicated and leads to many bugs.

For this reason, @optionsome and I agreed that HSL, who is the only remaining user of the FareComponent, is going to move off the old component based API to the new leg-based Fares API.

Timing

Before the removal can happen HSL must move their frontend to the new Fares API. @optionsome will report in this issue when this has happened.

Backwards-compatibility

HSL have agreed that they don't need backwards-compatibility with the old API which has been deprecated for a while. The types will stay in the GraphQL schema but it will always return an empty result.

[leonardehrenfried]

@optionsome @nurmAV Can you give an update on the removal?

[optionsome]

Digitransit no longer uses the old fare API.