MM-44542: Add timeout to S3 operations (#20648)

https://mattermost.atlassian.net/browse/MM-44542

```release-note
We add a new config setting AmazonS3RequestTimeoutMilliseconds under
FileSettings which sets a timeout for requests to AWS S3.

By default, the timeout is at 30 seconds.
```

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

i18n/en.json

@@ -7983,6 +7983,10 @@
     "id": "model.config.is_valid.allow_cookies_for_subdomains.app_error",
     "translation": "Allowing cookies for subdomains requires SiteURL to be set."
   },
+  {
+    "id": "model.config.is_valid.amazons3_timeout.app_error",
+    "translation": "Invalid timeout value {{.Value}}. Should be a positive number."
+  },
   {
     "id": "model.config.is_valid.atmos_camo_image_proxy_options.app_error",
     "translation": "Invalid RemoteImageProxyOptions for atmos/camo. Must be set to your shared key."