externals: Add catch2 v3.2.1

Merge commit '6879e5bb1c598a9a517d7bdec8ba1a0bace3ef10' as 'externals/catch'

externals/catch/tools/scripts/approve.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+
+import os
+import sys
+import shutil
+import glob
+from scriptCommon import catchPath
+
+rootPath = os.path.join( catchPath, 'tests/SelfTest/Baselines' )
+
+if len(sys.argv) > 1:
+    files = [os.path.join( rootPath, f ) for f in sys.argv[1:]]
+else:
+    files = glob.glob( os.path.join( rootPath, "*.unapproved.txt" ) )
+
+
+def approveFile( approvedFile, unapprovedFile ):
+    justFilename = unapprovedFile[len(rootPath)+1:]
+    if os.path.exists( unapprovedFile ):
+        if os.path.exists( approvedFile ):
+            os.remove( approvedFile )
+        os.rename( unapprovedFile, approvedFile )
+        print( "approved " + justFilename )
+    else:
+        print( "approval file " + justFilename + " does not exist" )
+
+if files:
+    for unapprovedFile in files:
+        approveFile( unapprovedFile.replace( "unapproved.txt", "approved.txt" ), unapprovedFile )
+else:
+    print( "no files to approve" )