Add CLI Base class for command line code (#25106)

spec/lib/mastodon/cli/ip_blocks_spec.rb

@@ -3,9 +3,15 @@
 require 'rails_helper'
 require 'mastodon/cli/ip_blocks'
 
-RSpec.describe Mastodon::CLI::IpBlocks do
+describe Mastodon::CLI::IpBlocks do
   let(:cli) { described_class.new }
 
+  describe '.exit_on_failure?' do
+    it 'returns true' do
+      expect(described_class.exit_on_failure?).to be true
+    end
+  end
+
   describe '#add' do
     let(:ip_list) do
       [