[BUG] Module name prevents vendoring this as a tool

[ojkelly]

What is the bug?
The project cannot be vendored as a tool. More info on the concept https://marcofranssen.nl/manage-go-tools-via-go-modules

How can one reproduce the bug?

1. either go install github.com/opensearch-project/opensearch-cli@main

go install github.com/opensearch-project/opensearch-cli@main                                        
go: github.com/opensearch-project/opensearch-cli@main: github.com/opensearch-project/opensearch-cli@v1.1.1-0.20220614170259-6cc9916c0aac: parsing go.mod:
        module declares its path as: opensearch-cli
                but was required as: github.com/opensearch-project/opensearch-cli

2. or running go mod tidy && go mod vendor with a tools.go file as follows

# tools.go

//go:build tools
// +build tools

// This package is used to enable vendoring of tooling used in the repo, that is
// run via cli, and not imported anywhere.
package tools

import (
	_ "github.com/opensearch-project/opensearch-cli"
)

What is the expected behavior?

The project to be vendored in the repo.

What is your host/environment?

• OS: macos
• Version: go 1.18
• Plugin version: n/a
• OpenSearch version: n/a

[wbeckler]

Seems like a worthwhile fix. Feel free to contribute a PR.