INTSAMPLES-148: Make JPA Sample as Boot App

JIRA: https://jira.spring.io/browse/INTSAMPLES-148

Upgrade several dependencies, especially OpenJPA-2.4.0 to support Java 8 Class Transformation

Upgrade to DSL-1.1.2 and other polishing

Upgrade to SI-4.3.0.M1

basic/jpa/src/main/resources/schema.sql

@@ -0,0 +1,8 @@
+drop table if EXISTS PEOPLE;
+DROP TABLE if EXISTS OPENJPA_SEQUENCE_TABLE;
+
+CREATE TABLE OPENJPA_SEQUENCE_TABLE (ID TINYINT NOT NULL, SEQUENCE_VALUE BIGINT, PRIMARY KEY (ID));
+
+CREATE TABLE SEQUENCE (SEQ_NAME VARCHAR(50), SEQ_COUNT DECIMAL(15));
+
+CREATE TABLE PEOPLE (id BIGINT generated by default as identity, name VARCHAR(255), CREATED_DATE_TIME TIMESTAMP, PRIMARY KEY (id));