Tracking issue: Update Blueprints to use the new writeFiles and proxy work

[bph]

This is a tracking issue to update Blueprints in the Gallery to use
Blueprints: Directory Resources
where appropriate.

Adds a Resource resource type that provides a name: string and files: FileTree.
Renames pluginZipFile to pluginData in theinstallPluginstep
Renames themeZipFile to themeData in the installPlugin step
Adds a new writeFiles step for writing entire directory trees
Adds a new literal:directory resource type where an entire file tree can be specified inline
Adds a new git:directory resource type

see also GitDirectoryResource #1858

As I went through all blueprints, I did a quick audit and added a few minor correction to the to-do-list

To-do List

• Update blueprint custom-post to use literal:directory i #91
• Update blueprint admin-notice to use the new writeFiles #90
• Update friends-cors to use writeFiles steps #93
• update gb-more-experiments + grid-variations #94
• Update install-activate-setup-theme #95
• Update install-plugin-from-Gist #96
• Update posts-via-wp-cli to use login shorthand #97
• update reset-data-and-import-content #98
• Update `Stylish Press! to use the shorthand for login and plugins #99
• update theme-a11y-test to use login shorthand #100
• Update tt5-demo #101
• Update Woo-shipping to use Install plugin with plugindata literal:directory #102
• Update Woocommerce-product-feed to use shorthands #103
• Update wp-cli add post w/ featured image write two files in one step #104
• update WPGraphQL using login shorthand #105

[bph]

With all listed tasks completed, this issue can be closed. Thank you to @bgrgicak for working through the PRs with me.