Motivation

We want to make it easier to add customizations when running localstack start. For instance, to generalize something like DNS_ADDRESS, we could just provide a port mapping for localstack start, that allows people to map, say, 127.0.0.1:1053:53/udp. Similarly, there's now easy way to mount custom volumes into the localstack container other than using DOCKER_FLAGS.

This PR adds a -p and -v flag to localstack start, which are the same as the flags used in docker run. This is a continuation of #8772

Changes

• Add -p/--publish and -v/--volume flags to localstack start
• Re-use and refactor the necessary code from dev configurators (was already there) into the bootstrap ContainerConfigurators
• Fixed an issue where volume parsing wasn't working correctly if :ro suffix was provided
• Fixed an issue in ports parsing that would prevent a /<protocol> suffix or port range <start>-<end> to be parsed correctly
• Added a unit test for the configurator