[Feature]: Calculate file hashes

### Description

Ability for file system plugin to calculate the hash of a file

### Platforms

- [x] iOS
- [x] Android
- [ ] Web

### Request or proposed solution

I am looking for a way to check if a file on the phone already exists on the server. To do that I need a common way to compare them. The simplest would be something like an MD5 check.

If this is a terrible idea, let me know. I haven't found a good way to do this through javascript, especially if the file is rather large.

### Alternatives

_No response_

### Additional Information

_No response_