Update WordPress.org CLI assets

[travistotz]

Updated all WordPress.org plugin directory assets with new branding images.

Description

Updated all WordPress.org plugin directory assets with new branding images:

• banner-1544x500.png
• banner-772x250.png
• icon-128x128.png
• icon-256x256.png

No code review needed, just review to make sure the assets will be properly updated on SVN on .org. https://github.com/gravityforms/gravityformscli

Related Issue

Closes: https://github.com/gravityforms/backlog/issues/7055

Testing

Testing Requirements

• This needs to be tested in multiple browsers.
• This needs to be tested with both Gravity and Orbital themes.
• This needs to be tested with and without AJAX submission.
• This needs accessibility testing.
• This needs to be tested with different versions of PHP or database servers.
• This needs to be tested with different versions of WordPress.
• None of the above.

Testing Instructions

Review of proper process for updating images on .org repo for CLI plugin.