[mercury][chat] Add official styles for the Chat component, improve markdown-viewer styles and add assistant-fill icon

[bsastregx]

Changes in this PR

Chat

• Add a custom item render for the renderItem property. Some features that the mercury custom item render includes are:

  • Styles for differentiating error, warning, and success status messsages.
  • A "header" for the assistant message, that displays an avatar, the assistant name, and the message time.
  • A "copy" button for copying the message.
  • A classical "three dots" animation for the "waiting" message type.

• A MercuryMessageMetadata type for the ChatMessage metadata is now exported in @genexus/mercury:

  type MercuryChatMessageMetadata = {
    assistantName: string;
    time?: string;
  }

• Improved code block styles

  Before	After

• Support for uploading files (audio, video, image, and application/file)
  

Markdown viewer

• Styles for the markdown viewer has been improved to match the Figma designs.

Breaking Changes

• Update @genexus/chameleon-controls-library to >= 6.20.0. At least this Chameleon version is required for the updated Chat styles to match.

• The size of the markdown-viewer headings has been reduced.