Add naming_provider::Error type

Add naming_provider::Error type

Summary:
Push .unwrap()s up a level by adding proper error handling in NamingProvider.

Some error-type boilerplate is derived by the [thiserror](https://docs.rs/thiserror/latest/thiserror/) crate.

The idea behind this design is that the Error type will contain variants for all possible implementations of NamingProvider. For instance, if we added an implementation of NamingProvider which has its own database implementation and directly interacts with the filesystem, we might add an `IoError(#[from] std::io::Error)` variant, even though a `SqliteNamingProvider` will never return it.

We can improve this type in the future by adding variants with higher-level meaning. For instance, if no file exists at the path of our SQLite database, we might return a new variant like:

```
    #[error("File not found: {path:?}")]
    DatabaseFileNotFound { path: PathBuf },
````

rather than a variant wrapping the (much-more-general) `rusqlite::Error` or `std::io::Error` types.

Reviewed By: shayne-fletcher

Differential Revision: D34461056

fbshipit-source-id: bb4b84dee2c7a162d5fa271d4a8dae4e08b1373a