Rename cardinality enum to match spec

[popematt]

Issue #, if available:

None

Description of changes:

Changes the ParameterCardinality enum so that the variants match the terms used in the spec.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Attention: Patch coverage is 70.58824% with 5 lines in your changes missing coverage. Please review.

Please upload report for BASE (ion-11-encoding@1c8be59). Learn more about missing BASE report.

Files	Patch %	Lines
src/main/java/com/amazon/ion/impl/macro/Macro.kt	44.44%	1 Missing and 4 partials ⚠️

Additional details and impacted files

@@                Coverage Diff                 @@
##             ion-11-encoding     #907   +/-   ##
==================================================
  Coverage                   ?   69.63%           
  Complexity                 ?     6461           
==================================================
  Files                      ?      184           
  Lines                      ?    25599           
  Branches                   ?     4599           
==================================================
  Hits                       ?    17825           
  Misses                     ?     6387           
  Partials                   ?     1387           

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