#2473 - Oracle - column alias - Change such that OraclePlatform doesn't use column alias

So with #2254 we regressed OraclePlatform to use column alias. This really should have introduced an Oracle12 platform instead. 18c onwards and we don't want the column alias.

ebean-api/src/main/java/io/ebean/config/dbplatform/oracle/Oracle11Platform.java

@@ -11,6 +11,7 @@ public class Oracle11Platform extends OraclePlatform {
   public Oracle11Platform() {
     super();
     this.platform = Platform.ORACLE11;
+    this.columnAliasPrefix = "c";
     this.sqlLimiter = new OracleRownumSqlLimiter();
     this.basicSqlLimiter = new OracleRownumBasicLimiter();
     dbIdentity.setIdType(IdType.SEQUENCE);

ebean-api/src/main/java/io/ebean/config/dbplatform/oracle/Oracle12Platform.java

@@ -0,0 +1,13 @@
+package io.ebean.config.dbplatform.oracle;
+
+/**
+ * Oracle 12 platform using column alias.
+ */
+public class Oracle12Platform extends OraclePlatform {
+
+  public Oracle12Platform() {
+    super();
+    //this.platform = Platform.ORACLE12;
+    this.columnAliasPrefix = "c";
+  }
+}

ebean-api/src/main/java/io/ebean/config/dbplatform/oracle/OraclePlatform.java

@@ -22,7 +22,6 @@ public class OraclePlatform extends DatabasePlatform {
   public OraclePlatform() {
     super();
     this.platform = Platform.ORACLE;
-    this.columnAliasPrefix = "c";
     this.supportsDeleteTableAlias = true;
     this.maxTableNameLength = 30;
     this.maxConstraintNameLength = 30;