feat: Support consul acl access control when discovering with consul or consul_kv

[hulining]

Description

When using consul and consul_kv as service discovery, it is hoped to support the incoming token to enable consul acl.

An example configuration file is as follows:

# for consul
discovery:
  consul:
    servers:
      - "http://127.0.0.1:8500"
      - "http://127.0.0.1:8600"
    token: "consul-access-token"  # add consul acl token config
    skip_services:
      - "service_a"
#...

# for consul_kv
discovery:
  consul_kv:
    servers:
      - "http://127.0.0.1:8500"
      - "http://127.0.0.1:8600"
    token: "consul-access-token"  # add consul acl token config
    prefix: "upstreams"
    skip_keys:
      - "upstreams/unused_api/"
#...

There is a discussion about consul acl in a similar issue #6692.

Official document of consul acl. And lua-resty-consul supports consul acl access control.

If the evaluation is feasible, please help to support it, thanks a lot~~

[Fabriceli]

Welcome to post a PR

[shreemaan-abhishek]

fixed by #10278