Remove GetByBean method because sometimes it's danger when query condition parameter is zero and also introduce new generic methods (#28220)

The function `GetByBean` has an obvious defect that when the fields are
empty values, it will be ignored. Then users will get a wrong result
which is possibly used to make a security problem.

To avoid the possibility, this PR removed function `GetByBean` and all
references.
And some new generic functions have been introduced to be used.

The recommand usage like below.

```go
// if query an object according id
obj, err := db.GetByID[Object](ctx, id)
// query with other conditions
obj, err := db.Get[Object](ctx, builder.Eq{"a": a, "b":b})
```

models/user/external_login_user.go

@@ -98,9 +98,10 @@ func GetExternalLogin(ctx context.Context, externalLoginUser *ExternalLoginUser)
 
 // LinkExternalToUser link the external user to the user
 func LinkExternalToUser(ctx context.Context, user *User, externalLoginUser *ExternalLoginUser) error {
-	has, err := db.GetEngine(ctx).Where("external_id=? AND login_source_id=?", externalLoginUser.ExternalID, externalLoginUser.LoginSourceID).
-		NoAutoCondition().
-		Exist(externalLoginUser)
+	has, err := db.Exist[ExternalLoginUser](ctx, builder.Eq{
+		"external_id":     externalLoginUser.ExternalID,
+		"login_source_id": externalLoginUser.LoginSourceID,
+	})
 	if err != nil {
 		return err
 	} else if has {
@@ -145,9 +146,10 @@ func GetUserIDByExternalUserID(ctx context.Context, provider, userID string) (in
 
 // UpdateExternalUserByExternalID updates an external user's information
 func UpdateExternalUserByExternalID(ctx context.Context, external *ExternalLoginUser) error {
-	has, err := db.GetEngine(ctx).Where("external_id=? AND login_source_id=?", external.ExternalID, external.LoginSourceID).
-		NoAutoCondition().
-		Exist(external)
+	has, err := db.Exist[ExternalLoginUser](ctx, builder.Eq{
+		"external_id":     external.ExternalID,
+		"login_source_id": external.LoginSourceID,
+	})
 	if err != nil {
 		return err
 	} else if !has {