🩹 [Patch]: Update Assert-GitHubContext error message to include context type info (#469)

This pull request introduces improvements to error handling and
messaging in PowerShell scripts related to GitHub context validation and
GraphQL query execution. The changes enhance clarity and provide more
detailed error information for debugging purposes.

- Fixes #468

### Improvements to error handling

* Enhanced error message formatting in `Assert-GitHubContext.ps1`:
Updated the error message to include the context name, type, and
required types in a more readable format. This improves clarity when the
context authentication type does not match the required types for a
command.

* Detailed GraphQL error messages in `Invoke-GitHubGraphQLQuery.ps1`:
Added a clear header ("GraphQL errors occurred") and moved the full
error details to the beginning of the error message. This change makes
the error output more structured and easier to interpret.

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: MariusStorhaug <[email protected]>
Co-authored-by: Marius Storhaug <[email protected]>

Author: Copilot

src/functions/private/Auth/Context/Assert-GitHubContext.ps1

@@ -53,9 +53,12 @@
         }
         if ($Context -eq 'Anonymous' -and $AuthType -contains 'Anonymous') { return }
         if ($Context.AuthType -in $AuthType) { return }
+
+        $errorText = "The context '$($Context.Name)' is of type [$($Context.AuthType)] which does not match the required" +
+        "types [$($AuthType -join ', ')] for [$command]."
         $PSCmdlet.ThrowTerminatingError(
             [System.Management.Automation.ErrorRecord]::new(
-                [System.Exception]::new("The context '$($Context.Name)' does not match the required AuthTypes [$AuthType] for [$command]."),
+                [System.Exception]::new($errorText),
                 'InvalidContextAuthType',
                 [System.Management.Automation.ErrorCategory]::InvalidArgument,
                 $Context

src/functions/public/API/Invoke-GitHubGraphQLQuery.ps1

@@ -60,21 +60,23 @@
                 $queryLines = $Query -split "`n" | ForEach-Object { $_.Trim() }
                 foreach ($errorItem in $graphQLResponse.errors) {
                     $errorMessages += @"
+
+GraphQL errors occurred:
+Full Error:
+$($errorItem | ConvertTo-Json -Depth 10 | Out-String)
+
 GraphQL Error [$($errorItem.type)]:
 Message:    $($errorItem.message)
 Path:       $($errorItem.path -join '/')
 Locations:
 $($errorItem.locations | ForEach-Object { " - [$($_.line):$($_.column)] - $($queryLines[$_.line - 1])" })
 
-Full Error:
-$($errorItem | ConvertTo-Json -Depth 10 | Out-String -Stream)
-
 "@
 
                 }
                 $PSCmdlet.ThrowTerminatingError(
                     [System.Management.Automation.ErrorRecord]::new(
-                        [System.Exception]::new("GraphQL errors occurred:`n$($errorMessages -join "`n`n")"),
+                        [System.Exception]::new($errorMessages),
                         'GraphQLError',
                         [System.Management.Automation.ErrorCategory]::InvalidOperation,
                         $graphQLResponse