Add wildcard back to end of tab completion command lookup (#9383)

Re-add wildcard when searching AST + Missed test case.

## PR Context

In #8109, we removed the line that added a wildcard to the end of the command that was used to match commands in the script AST. This readds that line closer to where it is used.

src/System.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs

@@ -103,6 +103,9 @@ namespace System.Management.Automation
 
                 if (lastAst != null)
                 {
+                    // We need to add the wildcard to the end so the regex is built correctly.
+                    commandName += "*";
+
                     // Search the asts for function definitions that we might be calling
                     var findFunctionsVisitor = new FindFunctionsVisitor();
                     while (lastAst.Parent != null)

test/powershell/Host/TabCompletion/TabCompletion.Tests.ps1

@@ -485,6 +485,7 @@ Describe "TabCompletion" -Tags CI {
                 @{ inputStr = '$A=[datetime]::now;$A.'; expected = 'Date'; setup = $null }
                 @{ inputStr = 'try { 1/0 } catch {};$error[0].'; expected = 'CategoryInfo'; setup = $null }
                 @{ inputStr = '$x= gps pwsh;$x.*pm'; expected = 'NPM'; setup = $null }
+                @{ inputStr = 'function Get-ScrumData {}; Get-Scrum'; expected = 'Get-ScrumData'; setup = $null }
                 @{ inputStr = 'function write-output {param($abcd) $abcd};Write-Output -a'; expected = '-abcd'; setup = $null }
                 @{ inputStr = 'function write-output {param($abcd) $abcd};Microsoft.PowerShell.Utility\Write-Output -'; expected = '-InputObject'; setup = $null }
                 @{ inputStr = '[math]::Co'; expected = 'Cos('; setup = $null }