Support migrations on source cockroachcloud of kind cockroach

### Version Information

Server Version:
CLI Version (for CLI related issue): v2.15.1

### Environment

Cloud (with CockroachDB Cloud)

### What is the current behaviour?

I am trying to follow the steps here ("[Hasura Cloud to Local Dev](https://github.com/hasura/github-integration-starter#moving-from-hasura-cloud-to-local-dev)") to manage my remote CockroachDB Cloud schema via the Hasura Github integration.

Unfortunately when I try to run `hasura migrate create init --from-server --endpoint https://myproject.hasura.app --admin-secret *mysecret*`, I get the error message: `time="2022-11-17T13:56:22+10:00" level=fatal msg="migrations on source cockroachcloud of kind cockroach is not supported"`

### What is the expected behaviour?

Cockroach-cli produces migrations files, allowing me to manage my CockroachDB schema from Hasura cloud (via Github integration).

### How to reproduce the issue?

1. Create a CockroachDB cloud account
2. Connect Hasura Cloud to CockroachDB Cloud
3. Run `hasura init myproject` then hasura migrate create init --from-server --endpoint https://myproject.hasura.app --admin-secret *mysecret*`

### Screenshots or Screencast

```
PS C:\proj\dvasdekis_try_hasura_cockroach\services\hasura> hasura migrate create init --from-server --endpoint https://myproject.hasura.app --admin-secret mysecret

? Select a database to use
> cockroachcloud

time="2022-11-17T13:56:22+10:00" level=fatal msg="migrations on source cockroachcloud of kind cockroach is not supported"
```

Start with the `hasura migrate create ... --from-server` command and trace where the `cockroachcloud` source of kind `cockroach` is rejected. Confirm the migration-generation path for this source and validate the expected result by reproducing the documented CockroachDB Cloud workflow; done means migration files are produced instead of the unsupported-source error.

Written by the indexing model from the issue text.