Initial support of Devfile 2.0 specification

Red Hat developer tooling is converging on the devfile format and as such it has evolved from the 1.0 specification used by Che / CodeReady Workspaces, to a new 2.x specification.

The initial 2.0 specification has been defined and is currently in use by odo.

Moving to the 2.0 specification is coupled with an architectural change in Che / CRW to a new DevWorkspace CRD. We are gradually looking to adopt both the DevWorkspace and Devfile 2.0 as defined in this upstream issue.

With this initial support:

• It will NOT be possible to have the Web Terminal operator running in the same cluster
• Support will not be enabled by default. A user must start CRW with the CLI cmd crwctl server:deploy --workspace-engine=dev-workspace. This can also be achieved through operator Hub and a flag

• A user will be to start a workspace with a factory link pointing to a git repo with a devfile 2.0, this includes the devfiles currently used by odo.
• Plugins in the devfile will NOT be supported as they are not part of the 2.0 specification, CRW will fail to load a workspace where these are specified as it is not a valid component type.
• Only a 'per user' namespace strategy will be supported
• Only single host routing will be supported
• We will re-introduce the latest version of the OpenShift Connector plugin, which will work with devfile 2.0, however this will not be the default version due to incompatibility with devfile 1.0. See CRW-1733 for followup work in 2.9
• Authentication is disabled for DevWorkspace based workspaces(anyone with the URL has access)

 
References: 

• Spec definition (common with odo, IBM Codewind) 
• DevWorkspace controller part 1 (support for OpenShift web terminals) DONE
• DevWorkspace controller part 2 (support for Che workspaces)