Because ext-phar sucks, tmp gets spammed by cache files for every thread when loading files from the phar on the fly.
Instead, we convert the `.phar` into a decompressed `.tar` in the tmp directory and require files from inside it. Surprisingly, this works because `ext-phar` supports `tar` and `zip` natively. No stream wrapper is required, as the `PocketMine.php` bootstrap loads files relative to its location, so the cache is automatically used for everything.
To be honest I would rather get rid of phars entirely, but they are still the easiest way to have PhpStorm load PocketMine-MP API information for now, and the alternatives are more complicated and inconvenient.
### Caveats
Everywhere that previously used `new Phar(Phar::running(false))` in the core code needs to be updated to use `PharData` for this to work correctly. Plugins don't need to do anything.
### Why not just use `Phar::decompressFiles()`?
This requires setting `phar.readonly` to `0`, which is a security issue. Technically, we could have used a subprocess to do this, but it just didn't seem right.
### WTF? `phar://` can be used on `tar` files???
Yup. I was just as surprised to find out that `require` works in such contexts.
### Relevant issues
- Closes#6214
## Changes
### API changes
None.
### Behavioural changes
Server startup will be slightly slower, as the phar has to decompress and convert itself into a `.tar`. However, testing showed that this generally takes less than 200 ms, so it should be barely noticeable.
## Backwards compatibility
No BC issues.
## Tests
Locally tested and the CI will also verify
