refactor(redis-v5): Move command 'redis:keyspace-notifications'

[sbosio]

Description

Moves the redis:keyspace-notifications command to CLI, converting to OClif Core and TS.

Test instructions

You can test by pulling this branch, installing dependencies with yarn and building with yarn build. Then run the following commands, knowing that if the app doesn't have any Redis add-on, you should see an error and in apps with more than one Redis add-on you should see an error unless you specify the DATABASE arg.

./bin/run redis:keyspace-notifications --help                                         # always test that help looks ok.
./bin/run redis:keyspace-notifications -a test_app_without_redis                      # shows error.
./bin/run redis:keyspace-notifications -a test_app_single_redis -c AKE                # sets the notifications config.
./bin/run redis:keyspace-notifications -a test_app_single_redis -c ""                 # resets the notifications config.
./bin/run redis:keyspace-notifications -a test_app_multiple_redis                     # shows error.
./bin/run redis:keyspace-notifications addon-name -a test_app_multiple_redis -c AKE   # sets the notifications config.

You can add Heroku Redis add-ons to any test app with heroku addons:create heroku-redis -a test-app.

SOC2 Compliance GUS Work Item