Improve presentation of published port ranges

[thaJeztah]

fixes #178

Port mappings in docker service ls are quite verbose, and occupy a lot of
space when ranges of ports are published.

This patch improves the output by reconstructing ranges of ports.

Given the following service;

$ docker service create \
  -p 60-61:60-61 \
  -p 62:61 \
  -p 80:80 \
  -p 81:80 \
  -p 90-95:90-95 \
  -p 90-92:90-92/udp \
  -p 93-96:93-96/udp \
  --name foo \
  nginx:alpine

Before this patch is applied:

$ docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE               PORTS
u1kwguv841qg        foo                 replicated          1/1                 nginx:alpine        *:60->60/tcp,*:61->61/tcp,*:62->61/tcp,*:80->80/tcp,*:81->80/tcp,*:90->90/tcp,*:91->91/tcp,*:92->92/tcp,*:93->93/tcp,*:94->94/tcp,*:95->95/tcp,*:90->90/udp,*:91->91/udp,*:92->92/udp,*:93->93/udp,*:94->94/udp,*:95->95/udp,*:96->96/udp

After this patch is applied:

$ docker service ls
ID                  NAME                MODE                REPLICAS            IMAGE               PORTS
u1kwguv841qg        foo                 replicated          1/1                 nginx:alpine        *:60-62->60-61/tcp,*:80-81->80/tcp,*:90-95->90-95/tcp,*:90-96->90-96/udp

Additional enhancements can still be made, and marked as TODO in this change;

• combine non-consecutive ports mapped to a single port (80->80, 81->80,
  84->80, 86->80, 87->80); to be printed as *:80-81,84,86-87->80.
• combine tcp and udp mappings if their port-mapping is the same;
  print *:80-81->80-81/tcp+udp instead of *:80-81->80-81/tcp, *:80-81->80-81/udp

- Description for the changelog

* Improve presentation of published ports by combining port-ranges [docker/cli#581](https://github.com/docker/cli/pull/581)

[thaJeztah]

ping @dnephin @vdemeester @jefflill PTAL

While working on this, I noticed that various commands include the formatted values when using --format '{{ json . }}'. I think we should look at that, and always print the raw values when printing JSON (not sure there's a way to do that on a "global" level, or if that has to be fixed for each command separately.

[codecov-io]

Codecov Report

Merging #581 into master will increase coverage by 0.14%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #581      +/-   ##
==========================================
+ Coverage   49.37%   49.52%   +0.14%     
==========================================
  Files         208      208              
  Lines       17178    17225      +47     
==========================================
+ Hits         8482     8530      +48     
+ Misses       8263     8262       -1     
  Partials      433      433

[thaJeztah]

ping @dnephin @vdemeester 🤗

[dnephin]

LGTM

[vdemeester]

LGTM 🎉