Fix: Remove commands that trigger Arista EOS bug from collected config (#2585)

Arista cEOS fails to replace a configuration if the new configuration
contains "no lldp X" on the management interface. This commit
provides a generic "collected configuration cleanup" mechanism
and uses it to remove "no lldp transmit" and "no lldp receive"
configuration commands.

Closes #2577

Author: ipspace

netsim/ansible/tasks/fetch-config/_config_cleanup.j2

@@ -0,0 +1,4 @@
+{% for line in ansible_net_config.split('\n') 
+     if line.strip() not in netlab_config_remove|default([]) %}
+{{   line }}
+{% endfor %}

netsim/ansible/tasks/fetch-config/eos.yml

@@ -3,3 +3,6 @@
 ---
 - arista.eos.eos_facts:
     gather_subset: config
+
+- set_fact:
+    ansible_net_config: "{{ lookup('template','_config_cleanup.j2') }}"

netsim/devices/eos.yml

@@ -13,6 +13,9 @@ group_vars:
   ansible_ssh_pass: vagrant
   ansible_network_os: eos
   ansible_connection: network_cli
+  netlab_config_remove:
+  - no lldp transmit
+  - no lldp receive
 features:
   initial:
     system_mtu: true