Reuse network for e2e test

[ylg-avalabs]

Why this should be merged

• Reuse network for e2e tests. It saves time to setup e2e tests.

How this works

• The network info is persisted in a directory. When running the e2e tests, we load the network from the directory and reuse the network.
• To reuse the network:

./scripts/e2e_test.sh --components teleporter --network-dir <network directory>

If the directory does not exist or is empty, it will be used as the root network directory for a new network.
If the directory exists and is non-empty, the network will be reused.

How this was tested

• e2e tests

How is this documented

[geoff-vball]

Like I commented on the icm-services PR, I think it would make the most sense if you specify a network_dir that doesn't exist, we should spin up a new network and save it to that directory instead of failing. That way you can specify where you want to save the network, and you can keep the same invocation on the command line between your first and subsequent runs.