feat: Added config switches to disable file renaming and Sample/Proof filtering

[piefke84]

This PR adds two config switches to the UI and config file.

1. By default, Altmount renames single file NZBs to the NZB name, which causes issues for some use cases. The switch "Allow file renaming during NZB import" (allow_file_renaming) allows disabling this functionality. Files will then be imported as present in the NZB/nested RAR archives.

Example: The NZB for Need.for.Speed.Undercover.CLONEDVD.WORKiNG.NFOFiX-0x0008 contains a single file "0x0008.nfo". Currently that file is imported but renamed to the NZB name (e.g. "Need.for.Speed.Undercover.CLONEDVD.WORKiNG.NFOFiX-0x0008.nfo"). This switch allows to keep the original file name.

2. By default, Altmount filters files matching a pattern for "proof" and "sample" and skips the import. The switch "Filter Sample and Proof" (filter_sample_and_proof) allows disabling this functionality. Samples and Proofs will be imported alongside any other files.

Defaults are set to "true" for both switches, keeping the current behaviour.