Unit tests for excludeAction

Added unit tests for the following:
- For target type URL:
    - ExcludeAction explicitly set true
    - ExcludeAction explicitly set to false
    - ExcludeAction omitted
- ExcludeAction when target type is BPP
- ExcludeAction when target type is BAP
- ExcludeAction when target type is Publisher

pkg/plugin/implementation/router/testData/exclude_action_bpp.yaml

@@ -0,0 +1,10 @@
+routingRules:
+  - domain: ONDC:TRV10
+    version: 2.0.0
+    targetType: bpp
+    target:
+      url: https://mock_bpp.com/v2/ondc
+      excludeAction: true
+    endpoints:
+      - search
+      - init