Render UiKit-Block elements without using `@rocket.chat/fuselage`

[umangutkarsh]

As an EmbeddedChat developer

I need to: Render the UiKit-Block PreviewBlock.js without using fuselage imports.

So That: The bundle size is reduced by creating custom components.

Acceptance Criteria

• Custom MessageGenericPreview.js
• Custom MessageGenericPreviewContent.js
• Custom MessageGenericPreviewDescription.js
• Custom MessageGenericPreviewCoverImage.js
• Custom MessageGenericPreviewTitle.js
• Custom MessageGenericPreviewFooter.js
• Custom MessageGenericPreviewThumb.js
• Custom Box.js