fix: hop flows are not setting telemetry_int cookie correctly, added unit test for inter evpl

[viniarck]

Closes #52 Closes #25

This PR is on top of #51

Summary

• Fixed inter EVC hop flows cookie value
• No need to update the changelog this NApp hasn't been released yet

Local Tests

• Covered with unit tests using this topology and collected the stored flows:

               +----+                                              +----+
              5|    |6                                            5|    |6
           +---+----v---+            +------------+           +----+----v---+
        1  |            |            |            |           |             |1
    -------+            |3         2 |            |3        2 |             +-------
     vlan  |     s1     +------------+    s2      +-----------+    s3       | vlan
     101   |            |            |            |           |             | 102
           |            |            |            |           |             |
           +------------+            +------------+           +-------------+

End-to-End Tests

N/A yet