Applying conditional settings for PR Builds (microsoft#958)

AL-GO doesn't apply conditional settings on PR Builds. In BCApps we have
the following conditional setting in the project settings

```
"buildModes": [ "Translated" ],
"ConditionalSettings": [
        {
            "branches": [
                "releases/*.[0-5]"
            ],
            "settings": {
                "buildModes": [ "Translated", "Strict"]
            }
        }
    ]
```

Yet when you see the PR builds, it doesn't build in StrictMode: 
https://github.com/microsoft/BCApps/actions/runs/8044365490

In ReadSettings we only apply conditional settings if the branchname
matches the pattern in the setting. The problem is that the branchName
is set to GITHUB_BASE_REF which for PR builds triggered by the
pull_request trigger is the merge branch (e.g. refs/heads/merge/123).
The branch pattern for the conditional setting will therefore never
match on PR Builds.

Actions/AL-Go-Helper.ps1

@@ -521,6 +521,11 @@ function ReadSettings {
         [string] $repoSettingsVariableValue = "$ENV:ALGoRepoSettings"
     )
 
+    # If the build is triggered by a pull request the refname will be the merge branch. To apply conditional settings we need to use the base branch
+    if (($env:GITHUB_EVENT_NAME -eq "pull_request") -and ($branchName -eq $ENV:GITHUB_REF_NAME)) {
+        $branchName = $env:GITHUB_BASE_REF
+    }
+
     function GetSettingsObject {
         Param(
             [string] $path