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;

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

@@ -108,7 +108,7 @@ fn parses_more_bson_complexity() {
 // │ 4 │      │
 // ╰───┴──────╯
 
-#[cfg(feature = "database")]
+#[cfg(feature = "sqlite")]
 #[test]
 fn parses_sqlite() {
     let actual = nu!(
@@ -123,7 +123,7 @@ fn parses_sqlite() {
     assert_eq!(actual.out, "3");
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "sqlite")]
 #[test]
 fn parses_sqlite_get_column_name() {
     let actual = nu!(

crates/nu-command/tests/commands/query/db.rs

@@ -1,6 +1,6 @@
 use nu_test_support::{nu, pipeline};
 
-#[cfg(feature = "database")]
+#[cfg(feature = "sqlite")]
 #[test]
 fn can_query_single_table() {
     let actual = nu!(
@@ -16,7 +16,7 @@ fn can_query_single_table() {
     assert_eq!(actual.out, "4");
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "sqlite")]
 #[test]
 fn invalid_sql_fails() {
     let actual = nu!(
@@ -30,7 +30,7 @@ fn invalid_sql_fails() {
     assert!(actual.err.contains("syntax error"));
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "sqlite")]
 #[test]
 fn invalid_input_fails() {
     let actual = nu!(

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

@@ -1,5 +1,5 @@
 use nu_test_support::nu;
-#[cfg(feature = "database")]
+#[cfg(feature = "sqlite")]
 use nu_test_support::pipeline;
 
 #[test]
@@ -82,7 +82,7 @@ fn uses_optional_index_argument() {
     assert_eq!(actual.out, "[7, 8]");
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "sqlite")]
 #[test]
 fn binary_operator_comparisons() {
     let actual = nu!(
@@ -151,7 +151,7 @@ fn binary_operator_comparisons() {
     assert_eq!(actual.out, "42");
 }
 
-#[cfg(feature = "database")]
+#[cfg(feature = "sqlite")]
 #[test]
 fn contains_operator() {
     let actual = nu!(