Allow recursive keep_keys

[MPStudyly]

SUMMARY

This PR adds a parameter and functionality to the keep_keys filter introduced by https://github.com/ansible-collections/community.general/issues/8438 to allow recursive searches over nested lists of dicts. This is a draft for now, as it for sure needs some polishing. Also I was unsure if the checks performed should be moved to the according plugins_utils file. remove_keys and replace_keys are also not touched by this (yet), as I'd like to have some input on this first.

Due to no issue existing yet, I was unaware on how to name/number a changelog fragment appropriately. If I can simply use the ref number of the PR, I'll create one with that. If I have to open a feature request ticket, I'll do that.

ISSUE TYPE

• Feature Pull Request

COMPONENT NAME

keep_keys

ADDITIONAL INFORMATION

- name: Debug before change
  vars:
    router_static_routes:
    - address_families:
        - afi: "ipv4"
          routes:
            - description: "WANv4"
              dest: "0.0.0.0/0" # default route
              next_hops:
                - forward_router_address: "192.168.0.1"
        - afi: "ipv6"
          routes:
            - description: "WANv6"
              dest: "::/0" # default route
              next_hops:
                - forward_router_address: "2001:db8::1"
  run_once: true
  ansible.builtin.debug:
    msg: {{ groups.all | map('extract', hostvars) | community.general.keep_keys(target=['dest', 'forward_router_address']) }}

gives

TASK [Debug static routes non recursive] ****************************************
ok: [localhost] => 
  msg: []

while

- name: Debug adter change
  vars:
    router_static_routes:
    - address_families:
        - afi: "ipv4"
          routes:
            - description: "WANv4"
              dest: "0.0.0.0/0" # default route
              next_hops:
                - forward_router_address: "192.168.0.1"
        - afi: "ipv6"
          routes:
            - description: "WANv6"
              dest: "::/0" # default route
              next_hops:
                - forward_router_address: "2001:db8::1"
  run_once: true
  ansible.builtin.debug:
    msg: {{ groups.all | map('extract', hostvars) | community.general.keep_keys(target=['dest', 'forward_router_address'], recurse_lists=true)) }}

gives

TASK [Debug static routes recursive] ************************************
ok: [localhost] => 
  msg:
  - router_static_routes:
    - address_families:
      - routes:
        - dest: 0.0.0.0/0
          next_hops:
          - forward_router_address: 192.168.0.1
      - routes:
        - dest: ::/0
          next_hops:
          - forward_router_address: 2001:db8::1