feat(tests): added closing bracket test for formatting presets

[o-l-a-v]

PR Summary

Since #2158 is blocked due to PSScriptAnalyzer formatting limitations #2045 (comment) I thought I could at least add the relevant tests I created in that PR, without the proposed new preset OTPS.

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Change is not breaking
• Make sure all .cs, .ps1 and .psm1 files have the correct copyright header
• Make sure you've added a new test if existing tests do not effectively test the code changed and/or updated documentation
• This PR is ready to merge and is not Work in Progress.
  • If the PR is work in progress, please add the prefix WIP: to the beginning of the title and remove the prefix when the PR is ready.

[Copilot]

Pull request overview

Adds regression-style tests for Invoke-Formatter behavior around if/else close-brace placement across formatting presets, to preserve expected formatting semantics while broader preset work remains blocked upstream.

Changes:

• Adds new Pester context validating if/else formatting output for CodeFormattingAllman, CodeFormattingOTBS, and CodeFormattingStroustrup.
• Introduces canonical input/expected script definitions for the three brace styles and asserts formatter round-trips between them.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.