Stringify - Timeframe Enumeration --> String

Library "Stringify"
Cast variable types and enumerations to human-readable Strings

timeframe(string)
  Cast a timeframe enumeration to readable string.
  Parameters:
    string: `T` is a timeframe enumeration ('3D', '120', '15', '5s' ...)
  Returns: A string representation of the timeframe or 'NA' if `x` is `na`