validation: intra EVPLs with symmetric vlans or EPLs have to use a dedicated proxy port

[viniarck]

On EP033 it was explained and clarified all the configurations regarding proxy port.

Currently, we're enforcing that at least each UNI has a proxy port https://github.com/kytos-ng/telemetry_int/issues/31. However, we're not validating if this a proxy port is exclusive or not (and network operators, as documented on EP033 are responsible for the configuration and capacity planning), this is just a heads up that an intra evc evpl with symmetric vlans or EPLs if the same proxy port is used then in the sink before popping the int header, of one the matches would ended up being overwritten since they'd be the same. So, that's why I'll leave this issue documented, we can also start validating as a provisioning error if you guys wish for this case.

Here's an example with EVPL vlan 100 where a loop between interface 17 and 18, and both unis using proxy port 17:

{
    _id: '43538d26e776d6b32df8cfd246fd0656',
    flow: {
      owner: 'telemetry_int',
      cookie: Decimal128("12309065256900020299"),
      match: { in_port: 18, dl_vlan: 100 },
      instructions: [
        {
          instruction_type: 'apply_actions',
          actions: [
            { action_type: 'pop_int' },
            { action_type: 'set_vlan', vlan_id: 100 },
            { action_type: 'output', port: 15 }
          ]
        }
      ],
      table_id: 2,
      table_group: 'base',
      priority: 20000,
      idle_timeout: 0,
      hard_timeout: 0
    },
    flow_id: '9eadc44bad5f37ea37c41cd55d6e9259',
    id: '43538d26e776d6b32df8cfd246fd0656',
    inserted_at: ISODate("2023-08-25T18:01:28.347Z"),
    state: 'installed',
    switch: '00:00:00:00:00:00:00:01',
    updated_at: ISODate("2023-08-25T18:01:28.637Z")
  }