Remove inherent SimpleExpr methods that duplicate ExprTrait (#890)

* Remove `Expr`, re-export `Expr` as type alias of `SimpleExpr`

* Use `Self` in types

* Use `Self` in types

* Make `SimpleExpr::new` public and remove `new_with_left`

* Clippy

* Update `since`

* Update `since`

* Update `since`

* Remove inherent methods of `SimpleExpr` from `ExprTrait`

* Fix tests

* Fix tests

* Remove inherent methods on `Expr`

* Fmt

* Fix examples

* Fix

Author: Huliiiiii

examples/rusqlite/src/main.rs

@@ -1,6 +1,6 @@
 use chrono::{NaiveDate, NaiveDateTime};
 use rusqlite::{Connection, Result, Row};
-use sea_query::{ColumnDef, Expr, Func, Iden, Order, Query, SqliteQueryBuilder, Table};
+use sea_query::{ColumnDef, Expr, ExprTrait, Func, Iden, Order, Query, SqliteQueryBuilder, Table};
 
 use sea_query_rusqlite::RusqliteBinder;
 use serde_json::{Value as Json, json};

examples/sqlx_any/src/main.rs

@@ -1,7 +1,7 @@
 use chrono::NaiveDate;
 use sea_query::{
-    ColumnDef, Expr, Func, Iden, MysqlQueryBuilder, OnConflict, Order, PostgresQueryBuilder, Query,
-    QueryBuilder, SchemaBuilder, SqliteQueryBuilder, Table,
+    ColumnDef, Expr, ExprTrait, Func, Iden, MysqlQueryBuilder, OnConflict, Order,
+    PostgresQueryBuilder, Query, QueryBuilder, SchemaBuilder, SqliteQueryBuilder, Table,
 };
 use sqlx::{AnyPool, Row};
 use std::env;

examples/sqlx_mysql/src/main.rs

@@ -1,7 +1,9 @@
 use bigdecimal::{BigDecimal, FromPrimitive};
 use chrono::NaiveDate;
 use rust_decimal::Decimal;
-use sea_query::{ColumnDef, Expr, Func, Iden, MysqlQueryBuilder, OnConflict, Order, Query, Table};
+use sea_query::{
+    ColumnDef, Expr, ExprTrait, Func, Iden, MysqlQueryBuilder, OnConflict, Order, Query, Table,
+};
 use sea_query_binder::SqlxBinder;
 use sqlx::{MySqlPool, Row, types::chrono::NaiveDateTime};
 use time::{

examples/sqlx_postgres/src/main.rs

@@ -2,7 +2,7 @@ use bigdecimal::{BigDecimal, FromPrimitive};
 use chrono::{NaiveDate, NaiveDateTime};
 use rust_decimal::Decimal;
 use sea_query::{
-    ColumnDef, Expr, Func, Iden, OnConflict, Order, PostgresQueryBuilder, Query, Table,
+    ColumnDef, Expr, ExprTrait, Func, Iden, OnConflict, Order, PostgresQueryBuilder, Query, Table,
 };
 use sea_query_binder::SqlxBinder;
 use sqlx::{PgPool, Row};

examples/sqlx_sqlite/src/main.rs

@@ -1,5 +1,7 @@
 use chrono::{NaiveDate, NaiveDateTime};
-use sea_query::{ColumnDef, Expr, Func, Iden, OnConflict, Order, Query, SqliteQueryBuilder, Table};
+use sea_query::{
+    ColumnDef, Expr, ExprTrait, Func, Iden, OnConflict, Order, Query, SqliteQueryBuilder, Table,
+};
 use sea_query_binder::SqlxBinder;
 use serde_json::{Value as Json, json};
 use sqlx::{Row, SqlitePool};