add blueprint builder plugin

[ajitbohra]

blueprint-pr.mp4

Motivation for the change, related issues

#1755

Implementation details

WordPress Plugin to leverage Block Editor to build playground blueprints

Testing Instructions (or ideally a Blueprint)

build plugin

composer install
npm install
npm run build

Note:
PR will need changes to align with nx workspace

cc: @adamziel

[adamziel]

Closing this one – as discussed on the Hallway Hangout this PR is better suited for the https://github.com/WordPress/playground-tools/ repo.