Fix EZP-23390: Legacy IO loads whole file to get mime type with FS clust...

...er handler

Todo:
- [ ] Get [legacy PR](https://github.com/ezsystems/ezpublish-legacy/pull/1082) merged and change composer.json to reflect that before merging this
We should inject the existing `@ezpublish.core.io.mimeTypeDetector` into those handlers, and use `either getFromFile()` or `getFromBuffer()` depending on which is applicable.