Support new DMN 1.5 namespaces & schema

[saig0]

User Story (Required on creation)

As a developer, I want to be able to execute models compliant with the new DMN 1.5 standard, i.e. a model using the DMN 1.5 namespaces will be recognized as a DMN file and validated using the DMN 1.5 XML Schemas. It can be executed if it uses only the DMN features that we have implemented so far.

Functional Requirements (Required before implementation)

• to be decided: backporting

Technical Requirements (Required before implementation)

Limitations of Scope

This does not require the implementation of all changes that DMN 1.5 introduced over DMN 1.4.

Hints

• The DMN 1.5 specification is available for OMG members here: https://www.omg.org/members/spec/DMN/1.5/ (An OMG login can be requested here: https://www.omg.org/login/request). Additionally, the beta version is available publicly here: https://www.omg.org/spec/DMN/1.5/Beta1
• The solution keeps DMN 1.3 as the default namespace (e.g. for models that are generated with the model API)
• The C7 DMN model API is used in the C8, so this change is needed to support the new namespaces there
• The DMN TCK is now using DMN 1.4, which we want to test against (see https://github.com/camunda/camunda-bpm-platform/issues/2665 for the 1.4 ticket)

Links

Breakdown

### Pull Requests
- [ ] https://github.com/camunda/camunda-bpm-platform/pull/3599
- [ ] https://github.com/camunda/camunda-bpm-platform-maintenance/pull/1059
- [ ] https://github.com/camunda/camunda-bpm-platform-maintenance/pull/1058
- [ ] https://github.com/camunda/camunda-bpm-platform-maintenance/pull/1057

Dev2QA handover

• [ ] Does this ticket need a QA test and the testing goals are not clear from the description? Add a Dev2QA handover comment

[tmetzke]

I would recommend backporting the proposed PR to 7.17, 7.18, and 7.19. The PR is strictly additive and not influencing the existing DMN support and behavior (e.g. the version of DMN models created via Model API). This will allow us to support executing DMN 1.4 and 1.5 models in those versions as well without much effort.

[tmetzke]

To reviewer I backported the changes as-is to the maintenance branches. No adjustments were necessary, they are plain cherry-picks from the main branch.