feat: add basic error handling

Add anyhow::Result<()> return signature to all scripts and main.

src/scripts/postgres.rs

@@ -1,11 +1,12 @@
+use anyhow::Result;
 use std::path::PathBuf;
 
-pub fn import(path: &PathBuf) {
+pub fn import(path: &PathBuf) -> Result<()> {
     println!("{path:?}");
     todo!()
 }
 
-pub fn dump(path: &PathBuf) {
+pub fn dump(path: &PathBuf) -> Result<()> {
     println!("{path:?}");
     todo!()
 }