fix(video): add support for CMAF video format alongside DASH

[mtsz-pl]

Reddit has transitioned from DASH to CMAF video format. This change adds support for both formats to maintain compatibility.

Changes:

• Update REGEX_URL_VIDEOS to match both DASH and CMAF formats
• Add format capture group to preserve DASH/CMAF in URL path
• Add separate proxy endpoints for /vid/:id/dash/:size and /vid/:id/cmaf/:size
• Update format_url to handle 3-segment video URLs (id/format/size)
• Update tests to reflect new URL format with format segment

Video URLs now follow pattern: /vid/{id}/{format}/{size}.mp4 Example: /vid/abc123/cmaf/720.mp4

Fixes #503 Fixes #504