Add support for plugins

[spatterIight]

Closes #14

Tested and verified working with the following configuration:

devture_traefik_plugin_support_enabled: true

devture_traefik_configuration_extension_yaml: |
  providers:
    file:
      directory: /config/
      watch: true
      filename: ""
  serversTransport:
    insecureSkipVerify: true

  experimental:
    plugins:
      geoblock:
        moduleName: "github.com/PascalMinder/geoblock"
        version: "v0.2.8"

aux_file_definitions:
  - dest: "{{ devture_traefik_config_dir_path }}/element.spatterlight.space.yml"
    content: |
      http:
        routers:
          element-router:
            rule: Host(`element.spatterlight.space`)
            service: element-service
            entryPoints:
              - web-secure
            tls:
              certResolver: default
            middlewares:
              - geoblock-middleware

        middlewares:
          geoblock-middleware:
            plugin:
              geoblock:
                silentStartUp: false
                allowLocalRequests: false
                logLocalRequests: false
                logAllowedRequests: false
                logApiRequests: false
                ignoreAPITimeout: false
                api: "https://get.geojs.io/v1/ip/country/{ip}"
                apiTimeoutMs: 750
                cacheSize: 15
                forceMonthlyUpdate: true
                allowUnknownCountries: false
                unknownCountryApiResponse: "nil"
                blackListMode: false
                addCountryHeader: false
                countries:
                  - US

        services:
          element-service:
            loadBalancer:
              servers:
                - url: "http://172.24.16.2:80"
    owner: "traefik"
    group: "traefik"