🩹 [Patch]: Sort the return for Get-GitHubContext (#505)

## Description

This pull request focuses on improving the usability and consistency of
the GitHub context management PowerShell module. The main changes
include renaming parameter sets and internal logic for clarity, ensuring
output is sorted for better user experience, and updating the context
completer for more accurate and user-friendly suggestions.

- Fixes #503

**Parameter set and logic improvements:**

* Renamed parameter sets in `Get-GitHubContext.ps1` for clarity (e.g.,
`'NamedContext'` to `'Get a named context'`, `'ListAvailableContexts'`
to `'List all available contexts'`) and updated corresponding internal
logic and debug messages for consistency.

**Output and completion enhancements:**

* Sorted the output of contexts by name in `Get-GitHubContext.ps1` to
provide a more organized and predictable result.
* Moved `completers.ps1` from the private to public directory, and
updated the context completer to suppress debug output, sort and
deduplicate context names, and improve the accuracy of completion
suggestions.

## Type of change

<!-- Use the check-boxes [x] on the options that are relevant. -->

- [ ] 📖 [Docs]
- [ ] 🪲 [Fix]
- [x] 🩹 [Patch]
- [ ] ⚠️ [Security fix]
- [ ] 🚀 [Feature]
- [ ] 🌟 [Breaking change]

## Checklist

<!-- Use the check-boxes [x] on the options that are relevant. -->

- [x] I have performed a self-review of my own code
- [x] I have commented my code, particularly in hard-to-understand areas

Author: MariusStorhaug

src/functions/public/Auth/Context/Get-GitHubContext.ps1

@@ -19,20 +19,20 @@
         Justification = 'Encapsulated in a function. Never leaves as a plain text.'
     )]
     [OutputType([GitHubContext])]
-    [CmdletBinding(DefaultParameterSetName = '__AllParameterSets')]
+    [CmdletBinding(DefaultParameterSetName = 'Get default context')]
     param(
         # The name of the context.
         [Parameter(
             Mandatory,
-            ParameterSetName = 'NamedContext'
+            ParameterSetName = 'Get a named context'
         )]
         [Alias('Name')]
         [string] $Context,
 
         # List all available contexts.
         [Parameter(
             Mandatory,
-            ParameterSetName = 'ListAvailableContexts'
+            ParameterSetName = 'List all available contexts'
         )]
         [switch] $ListAvailable
     )
@@ -45,11 +45,11 @@
 
     process {
         switch ($PSCmdlet.ParameterSetName) {
-            'NamedContext' {
-                Write-Debug "NamedContext: [$Context]"
+            'Get a named context' {
+                Write-Debug "Get a named context: [$Context]"
                 $ID = $Context
             }
-            'ListAvailableContexts' {
+            'List all available contexts' {
                 Write-Debug "ListAvailable: [$ListAvailable]"
                 $ID = '*'
             }
@@ -85,12 +85,11 @@
                     throw "Unknown context type: [$($contextObj.Type)]"
                 }
             }
-        }
+        } | Sort-Object -Property Name
     }
 
     end {
         Write-Debug "[$stackPath] - End"
     }
 }
 #Requires -Modules @{ ModuleName = 'Context'; RequiredVersion = '8.1.3' }
-

src/functions/private/Auth/Context/completers.ps1 renamed to src/functions/public/Auth/Context/completers.ps1

@@ -12,7 +12,8 @@
         $contexts += 'Anonymous'
     }
 
-    $contexts += (Get-GitHubContext -ListAvailable -Verbose:$false).Name
+    $contexts += (Get-GitHubContext -ListAvailable -Verbose:$false -Debug:$false).Name
+    $contexts = $contexts | Sort-Object -Unique
     $contexts | Where-Object { $_ -like "$wordToComplete*" } | ForEach-Object {
         [System.Management.Automation.CompletionResult]::new($_, $_, 'ParameterValue', $_)
     }