[TOB-220,187,28] feat: v0.4.0 Textblocks&comments

Commit contains all backend tasks for the fourth sprint.

The focus of sprint 4 was to:
- create a concept for the statement response text-blocks
- add text-block draft persistence functionality
- add interfaces to add statement comments by the controibutors
- streamline date formats
- provide statement process history for already finished processes

Details:

[TOB-237] feat: comment interfaces

- fix date format for comment entries in database, WorkflowDataService
and test cases

[TOB-220] doc: textblock concept

- added json structure definitions of text block definition and
  textarrangement
- format table column size

[TOB-237] feat: Add editable flag to CommentModel

- added editable boolean flag to comment
- added userName parameter to userInfo

[TOB-222,223,224] feat: backend Textbausteine

- fixed code smell in new text block code

[TOB-222,223,224] feat: backend Textbausteine

- added database repositories to read textblockdefinition
- added database repositories to read and write drafts
- added TextblockService backend logic for textblock and draft access
- added TextblockController for access textbloc and draft via REST
- added test cases for TextblockController and TextblockService
- update openapi REST interface specification
- added current database create sql script

TOB[229,237] feat: Add Workflowdata interfaces

- automatically reference latest departmentstructure in statement when
  creating a new statement

[TOB220] doc: add textblock concept

- added section for textblock concept

TOB[229,237] feat: Add Workflowdata interfaces

- fix sonar bug optional get without check.

TOB[229,237] feat: Add Workflowdata interfaces

- added database repositories for Workflowdata and all related database table
  repositories and classes

- added interface to add and remove comments
- added interface to specify the workflowdata and required departments
- added test cases to verify the new implementation

[TOB-225] test: Test cases get WorkflowDiagram

- added testcases for the new REST interface to get a WorkflowDiagram
  all including all involved service interfaces.

[TOB-225] feat: Workflow XML API

- added API to GET the workflow diagram as BPMN XML

Signed-off-by: Tobias Stummer <stummer@develop-group.de>