fix(database): add indices to h2 to prevent deadlock on database

- also use naming scheme with 3 digits as patch level

related to #CAM-2567
test(db-upgrade): add patch scripts to sql jar and upgrade test

- the camunda-sql-scripts-XXX.jar now contains the concatenated
  patches of the last version and the current version
- patches from the last version enterprise are need for the current
  test of the current community version
- patches from the current enterprise version are need for
  the test of the current enterprise edition

- to the db upgrade test are two new phases added the sequence is now:
  1. create old version
  2. patch old version
  3. upgrade to current version
  4. patch current version
  5. execute tests
- with this test sequence we do not need a new test but have
  to enable the test for the last final version in jenkins

related to #CAM-2578