Feature cleanup (#7182)

Following up on #7180 with some feature cleanup:

- Move the `database` feature from `plugin` to `default`
- Rename the `database` feature to `sqlite`
- Remove `--features=extra` from a lot of scripts etc. 
- No need to specify this, the `extra` feature is now the same as the
default feature set
- Remove the now-redundant 2nd Ubuntu test run

crates/nu-command/tests/commands/mod.rs

@@ -53,7 +53,7 @@ mod path;
 mod platform;
 mod prepend;
 mod print;
-#[cfg(feature = "database")]
+#[cfg(feature = "sqlite")]
 mod query;
 mod random;
 mod range;