feat(): achievement viewer & support for Epic Games

[phobos665]

Description

Epic Achievement & Viewer support.

Note: Leaving out notifications as that's a larger piece of work that is more experimental.

Also contains a minor fix where epic games were launching offline unnecessarily.

Breakdown:

• Integrates seamlessly into the Achievements components for LibraryAppScreen
• Shows the icons, names, description and unlock/lock correctly.
• Created new data class for EpicAchievement for easy conversion to the generic Achievement
• Created EpicAchievementManager to specifically handle GraphQL queries with Epic servers to pull achievement data.

Recording

Type of Change

• Bug fix
• Performance / stability improvement
• Compatibility improvements
• Other (requires prior approval)

Checklist

• If I have access to #code-changes, I have discussed this change there and it has been green-lighted. If I do not have access, I have still provided clear context in this PR. If I skip both, I accept that this change may face delays in review, may not be reviewed at all, or may be closed.
• This change aligns with the current project scope (core functionality, stability, or performance). If not, it has been explicitly approved beforehand.
• I have attached a recording of the change.
• I have read and agree to the contribution guidelines in CONTRIBUTING.md.