fix: give container name to resolve discrepancies between different docker builds

[jcstein]

Overview

Pairs with celestiaorg/nitro#3
PR #4 changed the name of the path in the auth token setting of test-node.bash, but it is not standard across different operating systems.

Problem

Example on macOS when container is named nitro-testnode-da-1 :

✔ Container nitro-testnode-da-1              Started                   0.6s
Waiting for http://localhost:26659/header/1 to come up..........................................................................Done!
Error response from daemon: No such container: nitro-testnode_da_1

Example on Ubuntu when container is named nitro-testnode_da_1 :

✔ Container nitro-testnode_da_1              Started                   0.6s
Waiting for http://localhost:26659/header/1 to come up..........................................................................Done!
Error response from daemon: No such container: nitro-testnode-da-1

Solution

Give the container a name: da-celestia, keeping things standard across different OS.

 ✔ Container da-celestia                      Started                   0.1s
Waiting for http://localhost:26659/header/1 to come up...........................................................Done!
== Generating l1 keys

Checklist

• New and updated code has appropriate documentation
• New and updated code has new and/or updated testing
• Required CI checks are passing
• Visual proof for any user facing features like CLI or documentation updates
• Linked issues closed with keywords

[jcstein]

@Ferret-san for review 🫡