Add Cloud shell terminal like Che editor.

[AndrienkoAleksandr]

What does this PR do?

Add Cloud shell terminal like Che editor.

It can be tested with the following Devfile:

metadata:
  name: cloud-shell
components:
  - reference: https://gist.githubusercontent.com/sleshchenko/c1cd908303b12684ac21e616c4cee1e9/raw/7e1dc5d106024af49fb1009af0c18792d2b1e328/meta.yaml
    type: cheEditor
    alias: cloudShell
  - memoryLimit: 256Mi
    type: dockerimage
    alias: dev
    image: 'eclipse/che-remote-plugin-openshift-connector-0.0.17:7.2.0'
    env:
      - value: '\[\e[34m\]>\[\e[m\]\[\e[33m\]>\[\e[m\]'
        name: PS1
apiVersion: 1.0.0

Referenced issue:

eclipse-che/che#15434
eclipse-che/che#15497

Depends on:

• Change che-machine-exec according to fast cloud-shell integration(server part) che-machine-exec#63
• Initial simple cloud-shell frontend che-machine-exec#64
• Add redirects from / to static folder che-machine-exec#77

[amisevsk]

Just tested and it works with the provided devfile. One minor detail is that the first >> prompt appears on a separate line, indented deeply:

[sleshchenko]

@amisevsk Sometimes it works fine for me

Sometimes it just hangs and I don't get my terminal working... I'll register a separate issue for cloud shell

[sleshchenko]

CloudShell editor is not stable for me for some reasons but it's not related to the current PR, will register a separate issue for that.

BTW Well done!