Move LoopBack4 related repos to new GH org

As [LoopBack joins the OpenJS Foundation](https://openjsf.org/blog/2021/06/02/loopback-joins-openjs-foundation-as-new-incubating-project/), we'll be moving the LoopBack4 related repos to the new GH org: https://github.com/loopbackio

Here are the repos:

1. Core
- [ ] [loopback-next](https://github.com/strongloop/loopback-next)
- [ ] [loopback-datasource-juggler](https://github.com/strongloop/loopback-datasource-juggler) - @marioestradarosa
- [ ] [strong-error-handler](https://github.com/strongloop/strong-error-handler)
- [ ] [explorer.loopback.io](https://github.com/strongloop/explorer.loopback.io)

2. Commonly used connectors and common modules
- [x] [loopback-connector-mysql](https://github.com/strongloop/loopback-connector-mysql)
- [x] [loopback-connector-postgresql](https://github.com/strongloop/loopback-connector-postgresql)
- [ ] [loopback-connector-mongodb](https://github.com/strongloop/loopback-connector-mongodb) - @dhmlau
- [x] [loopback-connector-rest](https://github.com/strongloop/loopback-connector-rest)
- [ ] [loopback-connector-mssql](https://github.com/strongloop/loopback-connector-mssql)
- [ ] [loopback-connector-soap](https://github.com/strongloop/loopback-connector-soap) - @marioestradarosa
- [ ] [loopback-connector-oracle](https://github.com/strongloop/loopback-connector-oracle)
- [x] [loopback-connector-cloudant](https://github.com/strongloop/loopback-connector-cloudant)
- [ ] [loopback-connector-cassandra](https://github.com/strongloop/loopback-connector-cassandra) - @marioestradarosa
- [ ] [loopback-connector-couchdb2](https://github.com/strongloop/loopback-connector-couchdb2) - @marioestradarosa
- [ ] [loopback-connector-db2](https://github.com/strongloop/loopback-connector-db2)
- [ ] [loopback-ibmdb](https://github.com/strongloop/loopback-ibmdb)
- [ ] [loopback-connector-dashdb](https://github.com/strongloop/loopback-connector-dashdb)
- [ ] [loopback-connector-ibmi](https://github.com/strongloop/loopback-connector-ibmi)
- [ ] [loopback-connector-grpc](https://github.com/strongloop/loopback-connector-grpc)
- [ ] [loopback-connector-kv-redis](https://github.com/strongloop/loopback-connector-kv-redis)
- [ ] [loopback-connector-openapi](https://github.com/strongloop/loopback-connector-openapi)
- [ ] [loopback-connector-sqlite3](https://github.com/strongloop-community/loopback-connector-sqlite3) - @marioestradarosa
- [ ] [loopback-connector-elastic-search](https://github.com/strongloop-community/loopback-connector-elastic-search)
- [ ] [loopback-connector-redis](https://github.com/strongloop-community/loopback-connector-redis) - @marioestradarosa
- [ ] [loopback-connector-kv-extreme-scale](https://github.com/strongloop/loopback-connector-kv-extreme-scale)
- [ ] [strong-soap](https://github.com/strongloop/strong-soap) - @marioestradarosa

3. Documentation, examples & extensions

- [ ] [loopback.io](https://github.com/strongloop/loopback.io) - @dhmlau
- [x] [loopback4-example-shopping](https://github.com/strongloop/loopback4-example-shopping)
- [ ] [loopback4-example-kafka](https://github.com/strongloop/loopback4-example-kafka)
- [ ] [loopback4-extension-grpc](https://github.com/strongloop/loopback4-extension-grpc)
- [x] [loopback-governance](https://github.com/strongloop/loopback-governance)

## Acceptance Criteria
For each repo:
- [ ] ~publish a release before moving, if there're changes not in a release yet~ the publish process is smooth after the move, so no need to do this step
- [ ] CI (GitHub Actions and Travis) continues to work
- [ ] uses DCO as contribution method and MIT/Artistic-2.0 license (most repos should be good according to [this](https://gist.github.com/dhmlau/a955bd7b3928df9d79ace0d6b28b5f4c#list-of-all-repos-that-are-part-of-the-project))
- [ ] Code of Conduct (reference: https://github.com/strongloop/loopback-next/blob/master/docs/CODE_OF_CONDUCT.md. Contact email needs to be updated there)

Start with the repository checklist and acceptance criteria in this issue, then review the referenced docs/CODE_OF_CONDUCT.md path and each listed repository's CI and publishing configuration. Done means the applicable repositories are moved to loopbackio and their CI, contribution method, licenses, and Code of Conduct requirements continue to meet the stated criteria.

Written by the indexing model from the issue text.