feat(bpmn-data): add insert statement representation
refactor(bpmn-data): refactor insert statements
refactor(bpmn-data): move escaping in sql to statement generation
feat(bpmn-data): add update statement representation
feat(bpmn-data): add update logic to data object specification
refactor(bpmn-data): refactor update statements where possible

- the 'expression' element cannot yet be handled, as it contains arbitrary
SQL
Merge branch 'bpmn_data' of github.com:BPMNData/camunda-bpm-platform into bpmn_data