✨ Replaced Rake exception with our own

Tasks not found produced Rake-specific exception that is confusing with all the other work to remove Rake from the direct experience of end users as well as beginning the process to move away from Rake. New exception message suppresses Rake messaging.

bin/cli_helper.rb

@@ -6,7 +6,10 @@
 # =========================================================================
 
 require 'app_cfg'
-require 'ceedling/constants' # From Ceedling application
+
+# From Ceedling application
+require 'ceedling/constants'
+require 'ceedling/exceptions'
 
 class CliHelper
 
@@ -246,7 +249,26 @@ def print_rake_tasks()
 
   def run_rake_tasks(tasks)
     Rake.application.collect_command_line_tasks( tasks )
-    Rake.application.top_level()
+
+    # Replace Rake's exception message to reduce any confusion
+    begin
+      Rake.application.top_level()
+
+    rescue RuntimeError => ex
+      # Check if exception contains an unknown Rake task message
+      matches = ex.message.match( /how to build task '(.+)'/i )
+
+      # If it does, replacing the message with our own
+      if matches.size == 2
+        message = "Unrecognized build task '#{matches[1]}'. List available build tasks with `ceedling help`."
+        raise CeedlingException.new( message )
+
+      # Otherwise, just re-raise
+      else
+        raise
+      end
+    end
+
   end