Add Mimetype lib and helper

[danielebogo]

Fixes #1933

This PR fixes the issue when the HTTP content type doesn't match the file type. To fix it we read the first part of the file and match the correct mime type using Swime. If the file and HTTP types don't match, we update the episode metadata and store the file with the correct type and extension.

To test

[!NOTE] Make sure you have FF useMimetypePackage enabled

• CI must be 🟢
• Try to download some episodes from: https://play.pocketcasts.com/podcasts/f77f2320-60c8-0139-33f3-0acc26574db2 https://play.pocketcasts.com/podcasts/e8a4ad80-09e9-013c-f5ae-0acc26574db2
• After the download you should play it normally
• You can also try with https://rts-vod-dd.akamaized.net/ww/15153718/d3f6e99d-7bdb-37eb-96e1-aaa67fa0a582.mp4

Checklist

• [x] I have considered if this change warrants user-facing release notes and have added them to CHANGELOG.md if necessary.
• [ ] I have considered adding unit tests for my changes.
• [ ] I have updated (or requested that someone edit) the spreadsheet to reflect any new or changed analytics.

[dangermattic]

	2 Warnings
:warning:	Modules/Server/Package.swift was changed without updating its corresponding Package.resolved. Please resolve the Swift packages in Xcode.
:warning:	This PR is assigned to the milestone 7.73 ❄️. The due date for this milestone has already passed. Please assign it to a milestone with a later deadline or check whether the release for this milestone has already been finished.

Generated by :no_entry_sign: Danger

[SergioEstevao]

This is working great, tested with all the podcasts we detected issues and all working great now. Just did some nitpick comments and suggestion to improve it.

[danielebogo]

I think it will be safer to also put a check on the FF on the MetadataTask class in line 51 , to avoid racing conditions between updates to contentType

@SergioEstevao MetadataTask didn't change as the metadata is set before having the file in the temp folder and it happens before the DownloadManager returns the downloaded location.