Create common library for devfile read and write

[elsony]

Create a common library for reading and writing devfiles.

MVP:

• This work will be started from the parser code in the odo repo (Refactor devfile parser code to produce a common devfile parser can work in all tools redhat-developer/odo#4073)
• Restructure the code in odo repo to extract the generic parser library (refactor out anything that is odo specific)
• Include any extra functions that is currently available in the existing devfile/parser repo but not available in the odo repo
• Move the common library to the devfile/parser repo (Move the common library extracted from Odo to the devfile/parser repo #183)
• Switch to use the parser from devfile/parser in odo repo (Switch to use the parser from devfile/parser in odo repo redhat-developer/odo#4117)
• Produce Kubernetes generated objects (Devfile parser library should generate Kube objects #181)
• Use the generators objects code from devfile/library in the odo repo (Use the generators from devfile/library redhat-developer/odo#4209)
• Basic support for common library functions required by the dev console (initial Kubernetes object generation piece to unblock openshift/console #184)

MVP+:

• Merged devfile validation with devworkspace

[yangcao77]

this issue has been done, closing this issue.