[BUG] Seasonal EDTF dates not displaying properly in item metadata

[Aryan-R-Patel]

What steps does it take to reproduce the issue?
Refer to https://memory.digital.utsc.utoronto.ca/61220/utsc81775 and you will be able to see 1981-21 instead of Spring 1981 (which is what should be displayed as per the EDTF standard)

When does this issue occur?
The issue occurs when you enter a seasonal code (21-41) in the month position of an EDTF date field. As
per EDTF standards, codes 21-24 represent Spring, Summer, Autumn, and Winter, etc.
Currently, the formatter does not map these codes to their human-readable labels.

Which page does it occur on?
It occurs on any Repository Item display page where an EDTF-formatted date field is visible in the metadata.
Example: https://memory.digital.utsc.utoronto.ca/61220/utsc81775

What happens?
The raw numeric value for the season is displayed instead of the season name. For example, a date stored as 1981-21 is rendered as 1981-21 instead of Spring 1981

To whom does it occur (anonymous visitor, editor, administrator)?
This occurs for all users viewing the item metadata.

What did you expect to happen?
The date should be formatted and displayed to be more human readable.
Example: Spring 1981 (for 1981-21)

Which version of Islandora are you using?
Version 2.17.2

Screenshots:
Image from https://memory.digital.utsc.utoronto.ca/61220/utsc81775 showcasing the problem:

[Aryan-R-Patel]

PR: #154

[joshdentremont]

This is the default behaviour when the formatter is set to '2 digit month'. If you change it to month spelled out it should say Spring.