Add a webview to generate a devfile without ansible-creator

[alisonlhart]

This PR adds a new webview for generating a devfile from a template, designed for Red Hat OpenShift Dev Spaces.

New Create Devfile Webview

Adds a view where devfiles can be generated. The options are: Destination Path, Ansible Project Name, Container Image, and Override.

• Destination Path: defaults to the first folder open in the current workspace, or an empty path. If the path is empty, a path must be entered into the text box before the devfile can be generated.
• Ansible Project Name: Ansible project the devfile is being added to
• Container Image: Image to use in the devfile
• Override: If a file named devfile.yaml already exists at the destination path, create a new one with the form details.

Logging

Adds log output to the webview form showing that the devfile was created or that an error occurred.

Open file options

Shows a toast notification if the devfile was created successfully, and highlights an option to open it in the editor.