Cleanup Challenge and Opportunity code, leave only Subspace

[ccanos]

Description

As a an Alkemio developer I want a clean codebase

Acceptance criteria

• [ ] Find unused code, there are still classes that mention Opportunity, and we are using Subspace now for them. Probably easier after #
• [ ] There are certain classes suffixed Legacy related to Challenges and Opportunities. Try to remove them.

Additional Context

• [ ] Cards: Space vs SpaceSubspace (new) vs SubspaceCard (old ChallengeCard)
• [ ] Opportunity route, all Opportunity pages and Opportunity layout (+admin)
• [ ] rm Opportunity Context, useOpportunity
• [ ] All Challenge pages except Home
• [ ] Try to remove JourneyTypeName or at least minimize usage
• [ ] From JourneyLevel, JourneyPath and SpaceType pick what suits most usages

To be reviewed:

• [ ] Find unused code, there are still classes that mention Opportunity, and we are using Subspace now for them. Probably easier after #
• [ ] There are certain classes suffixed Legacy related to Challenges and Opportunities. Try to remove them.

Additional Context

Figure out whether SpaceType is to stay. If it's related to Space Template, then decide what's rendered based on SpaceType and what on JourneyLevel or Path (icon may be on SpaceType while the word subspace vs space may depend on the level/path).

Cards:

• src/domain/journey/subspace/subspaceCard/SubspaceCard.tsx extends src/domain/journey/common/SpaceChildJourneyCard/SpaceChildJourneyCard.tsx (merge? child journey = subspace now)
• src/domain/journey/space/SpaceSubspaceCard/SpaceSubspaceCard.tsx used on /spaces page
• src/domain/journey/space/SpaceCard/SpaceCard.tsx used on MyDashboard and similar

Areas that will be affected

Client. Space and Subspace levels

Timebox to: