fix: correctly render nested quotes media attachments in quotes

[Khizarshah01]

Brief Title

Fix nested quoted media rendering and incorrect attachment metadata

Description

This PR fixes an issue where media attachments (images, audio, video) inside nested quoted messages were rendered as generic file attachments.

It also prevents misleading (0.00 kB) file size metadata from appearing on nested text only quotes.

Acceptance Criteria Fulfillment

• [x] Media attachments in nested quotes render correctly
• [x] Text-only nested quotes do not show download icons
• [x] Invalid or missing file size metadata is hidden

Fixes #1074

Video/Screenshots

PR Test Details

Note: The PR will be ready for live testing at https://rocketchat.github.io/EmbeddedChat/pulls/pr-<pr_number> after approval. Contributors are requested to replace <pr_number> with the actual PR number.