Align sample/default descriptors and types

Summary of outcomes for Data Standard 2.1

• Problem Addressed: The enumerations in the TermMap type do not match those in the sample descriptor file.
• High-level Reasoning: TermMap currently includes more of a term type category (e.g., "Semester", "Trimester", "Quarter") where the sample descriptor values are more specific (e.g., "Fall Semester", "First Trimester", "First Quarter"). These should align.
• Changes Made: Added the following enumerations to TermMap:
  ● Fall Semester
  ● Spring Semester
  ● Summer Semester
  ● First Trimester
  ● Second Trimester
  ● Third Trimester
  ● First Quarter
  ● Second Quarter
  ● Third Quarter
  ● Fourth Quarter

Original ticket description follows:

Some analysis has shown that there is not a sample/default descriptor for each type enumeration in the Data Standard, and this seems like a miss: if the value is a type, then it seems logical that it would also have a default descriptor.

Example is the ResponsibilityMap that has a type for "Discipline" but no default descriptor for the same concept.