Clean up `Result.unwrap` usages

[alexsnaps]

Adding the lint to our crate and server code should help finding and going about them

diff --git a/limitador-server/src/main.rs b/limitador-server/src/main.rs

-#![deny(clippy::all, clippy::cargo)]
+#![deny(clippy::all, clippy::cargo, clippy::unwrap_used)]
 
diff --git a/limitador/src/lib.rs b/limitador/src/lib.rs
 
-#![deny(clippy::all, clippy::cargo)]
+#![deny(clippy::all, clippy::cargo, clippy::unwrap_used)]

Not that all necessary have to go, but probably cleaning some of these up and possibly swapping them for .expect() would be desirable.

Crate has ~68 of them, while the server code has ~29 calls to unwrap() across all features

This probably relates to #131

[alexsnaps]

These is dependency to #131 for doing this properly...