Bug: Uploaded SRT files are saved as CSV

[benjaminbellamy]

Describe the bug
Uploading SRT files does not work, SRT files are saved as CSV.

CodeIgniter 4 version
dev-develop

Affected module(s)
CodeIgniter\HTTP\Files\UploadedFile

Expected behavior, and steps to reproduce if appropriate
Create a form.
Upload a file name test.srt.
Uploaded file is renamed test.csv instead of test.srt.

Context

• OS: Ubuntu 20.04
• Web server nginX
• PHP version 7.3

Proposed Solution
When a srt file is uploaded, its mime type is recognized as application/octet-stream.
Then CodeIgniter\Files\File->guessExtension() calls Mimes::guessExtensionFromType($this->getMimeType()); to get the file extension.
Since 'srt' only has ['text/srt', 'text/plain'] the first type matching application/octet-stream is returned : CSV.

So in order to make it work, in Config\Mimes.php we would just need to update srt to:
'srt' => ['text/srt', 'text/plain', 'application/octet-stream'],
Et voilà !

[lonnieezell]

Care to submit a PR for this?