Added the BeyondFacts Lab as a prototype (#1175)

app/SharedTools/I18NKeyHash.cs

@@ -0,0 +1,27 @@
+namespace SharedTools;
+
+/// <summary>
+/// Computes the hash which turns a text of T() or TB() into its I18N key.
+/// </summary>
+/// <remarks>
+/// The I18N collector and the app both use it: the collector for the text it reads from the source, the app for the
+/// string it gets at runtime. A multi-line text holds the line endings of the checkout it was compiled from, so the
+/// hash makes them equal first; otherwise, a build from a Windows checkout would find no translation for such a
+/// text. Texts without line breaks keep the hash they always had.
+/// </remarks>
+public static class I18NKeyHash
+{
+    /// <summary>
+    /// Computes the hash of a text.
+    /// </summary>
+    /// <param name="text">The text, as T() or TB() gets it.</param>
+    /// <returns>The 32-bit FNV-1a hash of the text with LF line endings.</returns>
+    public static uint Of(string text) => NormalizeLineEndings(text).ToFNV32();
+
+    /// <summary>
+    /// Turns CRLF and CR line endings into LF.
+    /// </summary>
+    /// <param name="text">The text.</param>
+    /// <returns>The text with LF line endings, or the text itself when it holds no CR.</returns>
+    public static string NormalizeLineEndings(string text) => text.Contains('\r') ? text.Replace("\r\n", "\n").Replace('\r', '\n') : text;
+}