Galley polysemy (3/5) - Access effects

[pcapriotti]

This PR turns placeholder access effect for internal APIs and external services into actual Polysemy effects.

Summary

• Implemented effects:
  • BrigAccess
  • BotAccess
  • SparAccess
  • GundeckAccess
  • ExternalAccess
  • FederatorAccess
• Removed placeholder Intra effect

Overall plan for the Polysemy refactoring of Galley

1. Turn Galley into a newtype over Sem, and introduce "access" effects.
2. Add "store" effects and convert Data code into interpretations.
3. Turn placeholders into actual effects. (this pr)
4. Add fine-grained Error effects, and integrate them with Servant.
5. Make Galley into a type synonym over Sem, and get rid of Galley0.

Checklist

• The PR Title explains the impact of the change.
• The PR description provides context as to why the change should occur and what the code contributes to that effect. This could also be a link to a JIRA ticket or a Github issue, if there is one.
• changelog.d contains the following bits of information:
  • A file with the changelog entry in one or more suitable sub-sections. The sub-sections are marked by directories inside changelog.d.

[mdimjasevic]

This is good. A few comments are inlined.