fix(server): updated default CSP config to support videos from V3 player

[l0ll098]

Description

Immich V3 added a new video player that had the side effect of breaking current CSP configuration on Chromium-based browsers, as also seen with issue #29441.

This PR addresses those issues by adding the missing CSP directive.
Fixes #29441

How Has This Been Tested?

• In order to test this, we have to enable the default CSP policy with the env variable IMMICH_HELMET_FILE.
• Run Immich V3 and upload a video
• With these changes applied, even Chromium-based browsers should have no problems in playing back the video you previously uploaded. Without those changes, Chromium didn't played the video and complained about missing CSP directives.

Checklist:

• I have carefully read CONTRIBUTING.md
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation if applicable
• I have no unrelated changes in the PR.
• I have confirmed that any new dependencies are strictly necessary.
• I have written tests for new code (if applicable)
• I have followed naming conventions/patterns in the surrounding code
• All code in src/services/ uses repositories implementations for database calls, filesystem operations, etc.
• All code in src/repositories/ is pretty basic/simple and does not have any immich specific logic (that belongs in src/services/)

Please describe to which degree, if any, an LLM was used in creating this pull request.

No LLMs were used.

[immich-push-o-matic]

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