Feat(plugins): Add arista.avd.batch_template action plugin

[ClausHolbechArista]

Change Summary

Add arista.avd.batch_template action plugin

Component(s) name

arista.avd.batch_template

Proposed changes

Creating batch_template plugin which can template multiple files without use of Ansible loops. The major downside of Ansible loops is that they are single-process, so all templating happens in serial. In batch_template we perform the templating in forks (respecting ansible_forks value).

module: batch_template
version_added: "4.0.0"
author: Arista Ansible Team (@aristanetworks)
short_description: Render Jinja2 template on multiple items and write result to individual files.
description:
  - Render Jinja2 template on multiple items and write result to individual files.
options:
  template:
    description: Path to Jinja2 Template file
    required: true
    type: str
  dest_format_string:
    description: Format string used to specify target file for each item. 'item' is the current item from 'items'. Like "mypath/{item}.md"
    required: true
    type: str
  items:
    description: List of strings. Each list item is passed to 'dest_format_string' as 'item' and passed to templater as 'item'
    required: true
    type: list

How to test

Tested offline using schema documentation generation.

Checklist

User Checklist

• N/A

Repository Checklist

• My code has been rebased from devel before I start
• I have read the CONTRIBUTING document.
• My change requires a change to the documentation and documentation have been updated accordingly.
• I have updated molecule CI testing accordingly. (check the box if not applicable)

[gmuloc]

could you add some section in the README.md for now as well (and yes we shall endeavour to automate this ;) )

[carlbuchmann]

LGTM
no tests added since this will be part of schema documentation pre-commit, once we merge this feature.