BACK-143: Rename engine-and-editor to core-api

[kare]

No description provided.

[linear]

BACK-143 Remove Canvas and Dashboard

We have communicated to the community that:

• On April 30th 2021, the Canvas and Dashboard features will be removed from the Streamr Core application and the associated API. This was decided by the DATA token holders through a governance vote. You will still be able to create and manage streams, data products, and Data Unions as usual after this change. If you don’t currently use the Canvas or Dashboard features of the Core application, the change won’t affect you and you won’t notice any difference.

So let's try to list here actions taken to try to meet that. According to sources we need:

1. Fork  engine-and-editor and streamr-platform repos, for "backup"
   1. backup can be called [name]archive, eg. engine-and-editor_archive
   2. From GitHub settings set the project as Archived
2. Canvas and Dashboard related code needs to be removed from the original repos
3. Once code is removed and all works, we can rename original repo:
   1. engine-and-editor repo and docker renamed as -> core-api
   2. streamr-platform repo and docker renamed as -> core-frontend

• There were some pull requests that need to be handled (sub tasks)? Done