UseAdmin.ts split by functionalities

[AidanLoran]

Description

UseCoach.ts is long and contains many different functionalities inside of the one composable. It's harder to read and debug this way, and since it will undergo further development with the coach/team/class implementation, we should probably split it by page/functionality

TODO

• Separate Composable for Announcement
• Separate Composable for Form History
• Separate Composable for Form Builder
• Separate Composable for Class Progress (old work soon to be deprecated

Additional notes

useRaffleSpin.ts is already done this way, can reference it