Make Hover Window Transparent too when Transparent is True

[Aliqyan-21]

Description

Darkvoid aims for minimalism and visual consistency, but when the user enables transparent = true, the theme should be truly transparent.
Currently, certain floating UI elements—particularly hover windows, LSP popups, and other float-based components—still render with a background color, breaking the transparency.

As shown above, the hover window background remains opaque even when transparent mode is enabled.

Expected Behavior

When transparent = true, all relevant highlight groups should respect the transparent background, including but not limited to:

• NormalFloat
• FloatBorder
• Pmenu
• PmenuSel
• PmenuSbar
• PmenuThumb
• CmpDocumentation
• CmpDocumentationBorder
• LspInfoBorder
• DiagnosticFloating*

All floating and popup windows (e.g., hover, completion menu, LSP signature help) should appear with a fully transparent background that matches the main editor area.

Steps to Reproduce

1. Set transparent = true in your Darkvoid config.
2. Trigger an LSP hover (e.g., K in normal mode).
3. Observe that the hover window background is still visible (not transparent).

Tasks

• Ensure all floating UI highlight groups respect transparency.
• Verify that LSP hover, completion, and diagnostic windows all inherit transparent backgrounds.
• Maintain minimalism and consistency with Darkvoid’s design philosophy.

Notes

This would greatly improve the theme’s aesthetics and fulfill the minimalist design principle by ensuring a seamless, distraction-free look across all UI layers.