* feat: add get_url to connect options
Add a get_url to connect options and implement it for all needed types;
include get_filename for sqlite. These changes make it easier to test
sqlx.
* refactor: use expect with message
* refactor: change method name to `to_url_lossy`
* fix: remove unused imports
Inlined format args make code more readable, and code more compact.
I ran this clippy command to fix most cases, and then cleaned up a few trailing commas and uncaught edge cases.
```
cargo clippy --bins --examples --benches --tests --lib --workspace --fix -- -A clippy::all -W clippy::uninlined_format_args
```
