Convert public-function parameter names to singular nouns with plural aliases

[hmmwhatsthisdo]

Context

Jira's API frequently uses plural-form nouns in API response properties (e.g. labels), JQL queries, etc. Some of JiraPS's cmdlet parameters are named in alignment with the corresponding API methods/parameters/etc.

On the other hand, PowerShell's cmdlet development guidelines recommend singular-noun parameter names instead of plural-form.

As a result, JiraPS has a mixture of:

• Strictly-plural parameter names
• Strictly-singular parameter names
• Singular parameter names with plural aliases
• Plural parameter names with singular aliases

This lack of homogeneity confuses users and impacts discoverability of features. For example, if a user calls New-JiraIssue with the -Labels parameter, but then tries changing New to Set, -Labels is no longer a valid parameter. Users may believe that Set-JiraIssue does not support updating labels, which is not accurate (the parameter name has simply changed to -Label)

Description

To align with PowerShell best practices and support backwards compatibility for users expecting JiraPS to use similar verbiage as the API, we should use singular-form parameter names with plural-form aliases.

Additional Information

#522 solved this for -Label (nee -Labels) in New-JiraIssue and Set-JiraIssue, but other cmdlets likely have similar problems.