iosxr tests: Initial work for 2.3 (#20883)

Ensure a loopback device exists for testing
Remove provider:
Default is to run task on Network, device, use delegate_to: localhost for local tasks.

test/integration/targets/prepare_iosxr_tests/tasks/main.yml

@@ -0,0 +1,12 @@
+---
+
+- name: Ensure we have loopback 888 for testing
+  iosxr_config:
+    src: config.j2
+
+
+# Some AWS hostnames can be longer than those allowed by the system we are testing
+# Truncate the hostname
+# http://jinja.pocoo.org/docs/2.9/templates/#truncate
+- set_fact:
+    shorter_hostname: '{{ inventory_hostname_short| truncate(10, True, "") }}'

test/integration/targets/prepare_iosxr_tests/templates/config.j2

@@ -0,0 +1,4 @@
+interface Loopback888
+ description test for ansible
+ shutdown
+