Add a function to RpkTool to create an allow topic ACL for a user.
A reusable part of acl_create_allow_cluster refactored.

Support --username/--password authentication options

Add a function to check if the producer is running

Log service name with progress messages so that in case of several
producers running at the same time, it is possible to understand
who is doing what

typos, renames, comments

when throughput group is matched, log the client address

Becasue of the unique_ptr involved, the default equality operator
does not work correctly here.

`throughput_control_group` gets additional matching criteria by ACL
principals (users, etc.). In yaml/json, there can now be a list of
principals the group must match besides client_id if provided. Only the
principal type `user` is supported in this commit.

Add user names to the matching pattern of throughput_control groups

acl_principal is now another key to snc_quotas_context. It is passed
from the connection_context to create the context by matching with
a tput ctrl group, and to verify whether the context is still valid.

A new test to verify that when a user matches a tput ctrl group,
the connections authenticated by the user are not throttled while
the rest still are.

to complement the logging of node configurations. Note that
cluster_config.yaml records cluster config when nodes stop, whlie
this log dumps the initial bootstrap config.

in tput group configuration, one can specify "service" instead of a
"user", and specify SR or PP as the service, which internally
transaltes into the corresponding acl principal