Correctly identify hyphenated and alias command names

[takmar]

Fixes #868

Problem:
After version 1.3.0, invoking commands with hyphenated and alias names does not function as expected.

Given a Thor class definition as follows:

Copy code
class Test < Thor
  desc "foo-bar", "an example task"
  def foo_bar
    puts "I'm a thor task!"
  end

  map "fb" => :foo_bar 
end

Attempting to invoke the command with a hyphenated and the alias command:

% bundle exec thor test:foo-bar

% bundle exec thor test:FB

Results in a failure to execute the specified command, even though the help output correctly lists the command and its alias.

This PR addresses the issue by implementing a fix in the find_class_and_command_by_namespace method, ensuring that it correctly identifies both hyphenated command names and their aliases.

[naomichi-y]

It worked correctly 👍