Add a setDosing method to DrugOrder that takes a DosingInstruction type

TODOs:

• Add the interface and classes that implemented it as shown below:
  DosingInstructions

  interface DosingInstructions {
    /* Report the type of dosing instructions */
    DosingType getType();
  
    /* Get human-readable version of dosing instructions for a particular locale
     * Note that not all dosing instructions can be localized, so the result, especially
     * any free text may remain in the original language.  In general, we expect that
     * most implementations will write orders in a single language and then want to
     * translate instructions to the patient's preferred language when printing orders
     * for the patient.  In all other cases, you will want to call this method with
     * the user's locale (i.e., <tt>context.getLocale()</tt>).
     */
    String getDosingInstructionsAsString(Locale locale);
  
    /* Serialize dosing instructions into order */
    void setDosingInstructions(DrugOrder order);
  
    /* Get dosing instructions from order */
    DosingInstructions getDosingInstructions(DrugOrder order);
  }
  

  SimpleDosingInstructions

  class SimpleDosingInstructions implements DosingInstructions {
    DosingType type = SIMPLE;
    Double dose;
    Concept doseUnits;
    Concept route;
    OrderFrequency frequency;
    Double duration;
    Concept durationUnits;
    Boolean asNeeded;
    String asNeededCondition;
    String administrationInstructions;
  }
  

  FreeTextDosingInstructions

  class FreeTextDosingInstructions implements DosingInstructions {
    DosingType type = FREE_TEXT;
    String instructions;
  }
  

• Add setDosing(DosingInstruction dosing) method to DrugOrder which should copy the fields from the passed in DosingInstructions object and set them on the DrugOrder instance as shown below:

  public void setDosing(DosingInstructions di) {
      di.setFieldsOn(this);
  }