Add scripts for building and managing RustDesk versions

- Implement Build-CustomRustDesk.ps1 to build RustDesk with specified version and configuration.
- Create Get-LastBuiltVersion.ps1 to retrieve the last built version from a state file.
- Add Get-LatestRustDeskVersion.ps1 to fetch the latest version from GitHub releases.
- Develop Invoke-RustDeskPipeline.ps1 to orchestrate the build and deployment process.
- Introduce Publish-Artifacts.ps1 for publishing build artifacts via SMB or SCP.
- Implement Set-LastBuiltVersion.ps1 to update the state file with the last built version.

scripts/Get-LastBuiltVersion.ps1

@@ -0,0 +1,18 @@
+function Get-LastBuiltVersion {
+  [CmdletBinding()]
+  param(
+    [Parameter(Mandatory = $true)]
+    [string]$StateFilePath
+  )
+
+  if (-not (Test-Path -LiteralPath $StateFilePath)) {
+    return $null
+  }
+
+  $content = Get-Content -LiteralPath $StateFilePath -Raw -ErrorAction Stop
+  if ([string]::IsNullOrWhiteSpace($content)) {
+    return $null
+  }
+
+  return $content.Trim()
+}