Import projects in theia IDE from a factory: read factory metadata from the client side

[sunix]

Description

Part of import projects which is a subtask of #9074

previous: implement git import in theia node (server) as a rest service #9218

-> read factory metadata from the client side

This issue could be splitted in several ones:

• Fix workspace loader: pass querystring to open IDE url for "predefined IDE" Fix workspace loader which should pass its query strings to the underlying alternate IDE #9370
• Implement in the Theia client side part that retrieve factory id from query string
• factory api call to retrieve factory.json having the factory id
• implement the extraction of metadata to be used for clonning the projects (having the factory.json)
• make the factory working

< Factory json used for testing (openshift, based on theia stack) >

{
  "v": "4.0",
  "name": "theia",
  "workspace": {
    "environments": {
      "default": {
        "machines": {
          "ws/theia": {
            "attributes": {
              "memoryLimitBytes": "547483648"
            },
            "servers": {
              "theia": {
                "attributes": {
                  "type": "ide"
                },
                "port": "3000",
                "protocol": "http"
              }
            },
            "volumes": {
              "projects": {
                "path": "/projects"
              },
              "theia": {
                "path": "/home/theia"
              }
            },
            "installers": [],
            "env": {}
          },
          "ws/dev": {
            "attributes": {
              "memoryLimitBytes": "547483648"
            },
            "servers": {
              "theia-dev": {
                "attributes": {},
                "port": "3030",
                "protocol": "http"
              }
            },
            "volumes": {
              "projects": {
                "path": "/projects"
              }
            },
            "installers": [],
            "env": {}
          }
        },
        "recipe": {
          "type": "openshift",
          "content": "kind: List\nitems:\n - \n  apiVersion: v1\n  kind: Pod\n  metadata:\n   name: ws\n  spec:\n   containers:\n    - \n     image: 'eclipse/che-theia:nightly'\n     name: theia\n     resources:\n      limits:\n       memory: 2048Mi\n    - \n     image: 'eclipse/che-dev:nightly'\n     name: dev\n     resources:\n      limits:\n       memory: 2048Mi\n",
          "contentType": "application/x-yaml"
        }
      }
    },
    "defaultEnv": "default",
    "projects": [
      {
        "links": [],
        "name": "theia",
        "attributes": {
          "contribute_to_branch": [
            "master"
          ]
        },
        "type": "blank",
        "source": {
          "location": "https://github.com/theia-ide/theia.git",
          "type": "git",
          "parameters": {
            "branch": "master"
          }
        },
        "path": "/theia",
        "problems": [],
        "mixins": [
          "pullrequest"
        ]
      }
    ],
    "name": "theia",
    "commands": [],
    "links": []
  },
  "id": "factorywzmemy9du9yrt9uq",
  "creator": {
    "name": "che",
    "created": 1523020205700,
    "email": "che@eclipse.org",
    "userId": "che"
  }
}