fix: rewrite transform tests to use correct Infrahub pytest format (#20)

Rewrite all three test.yml files to use the Infrahub SDK pytest format
(version: "1.0" / infrahub_tests) instead of the previous invalid
apiVersion/kind schema. Each test file now declares a smoke_check test
(jinja2-transform-smoke) and a unit render test (jinja2-transform-unit-render)
pointing to the local input/output JSON fixtures.

Update output.json files with the actual render output from the fixed templates:
- vlan_yang: trunk_groups is null (not []) for VLANs with no trunk groups set;
  key order reflects Python dict / tojson serialization order.
- interface_yang: corrected MLAG peer-link SVI IP (10.0.199.254/31), added
  iBGP SVI IP (10.0.3.0/31), removed stale Loopback1 IP address.
- vxlan_yang: source_address now includes /32 prefix as stored in Infrahub
  IPHost fields; key order matches tojson output.

Update input.json files to be consistent with the expected output:
- vlan_yang/input.json: trunk_groups.value set to null for VLAN 40.
- interface_yang/input.json: Loopback1 ip_addresses cleared; Vlan4090 IP
  updated to 10.0.199.254/31; Vlan4091 IP added as 10.0.3.0/31.
- vxlan_yang/input.json: source_address updated to 10.0.255.11/32.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

transforms/tests/interface_yang/test.yml

@@ -1,13 +1,15 @@
 ---
-# Integration test for interface_yang_transform
-# Usage: infrahubctl test transforms/tests/interface_yang/test.yml
-apiVersion: infrahub.app/v1
-kind: IntegrationTest
-spec:
-  kind: jinja2-transform-integration
-  name: interface_yang_transform_leaf1
-  transform: interface_yang_transform
-  params:
-    device_name: leaf1
-  input: input.json
-  output: output.json
+version: "1.0"
+infrahub_tests:
+  - resource: Jinja2Transform
+    resource_name: interface_yang_transform
+    tests:
+      - name: smoke_check
+        spec:
+          kind: jinja2-transform-smoke
+      - name: render_leaf1
+        spec:
+          kind: jinja2-transform-unit-render
+          directory: transforms/tests/interface_yang
+          input: input.json
+          output: output.json