MediaSourceTier next steps

[Him188]

• 统一代码的数据源排序算法. 考虑即将支持的手动排序. 检查 GetWebMediaSourceInstanceFlowUseCaseImpl 和 GetPreferredMediaSourceSortingUseCaseImpl 等.
• 删除 fastSelectSources fastMediaSourceIdOrder

Originally posted by @Him188 in #1813 (comment)