Springboot Integration tests improvements

Creation of CpsIntegrationSpecBase
Demonstration of test class implementing CpsIntegrationSpecBase in CpsPersistenceSpec
Tests use reduced liquibase steps, basic bookstore yang model and bookstore json payload

Issue-ID: CPS-1379
Signed-off-by: lukegleeson <luke.gleeson@est.tech>
Change-Id: I38202d0888808d08d85fce1aab45fc43e8b0cec3
12 files changed