Refactor RMRK Core User/Internal Functions

[HashWarlock]

Refactor User facing functions to emit Event in the internal functions and move permissions logic to the user facing functions.

Question:

• Should we move the Lock check to internal function or user facing function (Current solution uses first point)
  • Keeping them in user facing functions allows for downstream implementations to avoid adhering to a Lock during migrations and for custom pallet calls in the runtime to make changes that can bypass the lock
  • Putting them in the internal functions requires all downstream implementations to adhere to this logic and could cause complications for downstream

[h4x3rotab]

LGTM