Ensure L2 routing for IPv6 hosts

[spisarski]

What does this PR do?

Fixes #315 Manually added neighbor entry (IPv6 equivalent to ARP) to ip dev switch tunnel for IPv6 L2 ipv6_routing Removed -dip4 hook for destination MAC lookups (send_packets.py) and interface (receive_packets.py) in the test code. Now lookups are ocurring using the destination IP address from ARP cache for IPv4 & using get-mac library getmac.get_mac_address() for IPv6. Fixed IPv6 addresses in lab_trial topology (inet & host2 had same & ae was in a different subnet)

iperf3 will now work with IPv6 endpoints

Do you have any concerns with this PR?

no

How can the reviewer verify this PR?

Ensure CI doesn't fail

Any background context you want to provide?

Need to ensure IPv6 works like IPv6

Screenshots or logs (if appropriate)

Questions:

• Have you connected this PR to the issue it resolves? yes
• Does the documentation need an update? no
• Does this add new dependencies? Python - get-mac
• Have you added unit or functional tests for this PR? Updated the existing to reflect changes as well as added an additional call on the test client to IPv6 endpoints in the iperf.yml test case

[spisarski]

Run Tofino Environment Build

[spisarski]

Run Tofino lab trial build

[spisarski]

Run Tofino core build

[spisarski]

Run Tofino lab trial build

[spisarski]

Run Tofino lab trial build

[spisarski]

Run Tofino core build