[E2E] Add basics of the E2E suite

[h5law]

Summary

This PR ports over the basics of the gherkin suite from the old v1 repo. It contains a "help" test and a "send" test to ensure this works with k8s localnet.

Summary generated by Reviewpad on 14 Oct 23 11:55 UTC

This pull request includes several changes across multiple files:

1. In the file node.go, a new file has been added that provides functionalities related to interacting with a node using the pocketd binary. It includes the declaration of a package named e2e, import statements for required packages, variable definitions, struct definitions, interface declaration, and function implementations.

2. A new file named help.feature has been added in the e2e/tests directory. It defines a feature for the root namespace and includes a scenario for when a user needs help with the pocketd binary. The scenario includes steps for checking if the user has the binary installed, running the "help" command, verifying the expected output, and validating the error-free exit of the binary.

3. Changes in the file init_test.go involve importing necessary packages and libraries, defining a regular expression, declaring a struct, and implementing multiple test functions related to end-to-end testing and interacting with pocketd binary.

4. Another new file named send.feature has been added in the e2e/tests directory. It defines a feature called "Tx Namespace" with a scenario named "User can send uPOKT". This scenario tests if the user can successfully send 10000 uPOKT to another address using the pocketd binary.

5. The go.mod file has been modified to add new dependencies and update existing ones.

6. In the Makefile diff, modifications include updates to the POCKET_NODE variable assignment, addition of a new target test_e2e for running end-to-end tests, modification of the go_test target, and exclusion of the Makefile itself from a search pattern.

These changes add new files, functionalities, and dependencies to the codebase and make improvements to existing files.

Issue

Fixes (in part) 16

Type of change

Select one or more:

• New feature, functionality or library
• Bug fix
• Code health or cleanup
• Documentation
• Other (specify)

Testing

• Run all unit tests: make test_all_unit
• Verify Localnet manually: See the instructions [here](TODO: add link to instructions)

Sanity Checklist

• I have tested my changes using the available tooling
• I have performed a self-review of my own code
• I have commented my code, updated documentation and left TODOs throughout the codebase

[okdas]

I like that we removed an additional abstraction of a container here, as the test will run on a container on DevNet anyway. Thank you!

[Olshansk]

Took a look at this after it was merged. LGTM overall but requested a couple of improvements.