Adds bigip_iapp_template module (#25630)

This module can be used to upload and manage TCL iApps on a BIG-IP.
iApps can be added, removed and updated in place as needed. iApp
files should be provided to the module via Ansible lookups.

Unit tests are provided. Integration tests can be found here

https://github.com/F5Networks/f5-ansible/blob/devel/test/integration/bigip_iapp_template.yaml#L23
https://github.com/F5Networks/f5-ansible/tree/devel/test/integration/targets/bigip_iapp_template/tasks

test/units/modules/network/f5/fixtures/basic-iapp.tmpl

@@ -0,0 +1,25 @@
+sys application template good_templ {
+  actions {
+    definition {
+      html-help {
+        # HTML Help for the template
+      }
+      implementation {
+        # TMSH implementation code
+      }
+      macro {
+        # TMSH macro code
+      }
+      presentation {
+        # APL presentation language
+      }
+      role-acl { admin manager resource-admin }
+      run-as none
+    }
+  }
+  description "My basic template"
+  partition Common
+  requires-modules { ltm }
+  ignore-verification true
+  requires-bigip-version-min 11.6.0
+}