feature[wip]: [process-instance-migration] Modularize

[ingorichtsmeier]

Modularize the process instance migration

A first attempt to handle process instance migration is done.

Description

To support the discussion about the right modules that we want for process instance migration, this branch provides example files and descriptions of the modules

Additional context

closes #224

Testing your changes

no tests so far.

Types of changes

• Bug fix (non-breaking change which fixes an existing open issue)
• New feature (non-breaking change which adds functionality to an extension)
• Breaking change (fix or feature that would cause existing functionality of an extension to change)
• Documentation update (changes made to an existing piece of documentation)

Checklist:

• My code adheres to the syntax used by this extension.
• My pull request requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the Camunda Community Hub documentation.
• I have read the Pull Request Process documentation.
• I have added or suggested tests to cover my changes suggested in this pull request.
• All new and existing CI/CD tests passed.
• I will /assign myself this issue, and add the relevant [issue labels] to it if they are not automatically generated by Probot.
• I will tag @camunda-community-hub/devrel in a new comment on this issue if 30 days have passed since my pull request was opened and I have not received a response from the extension's maintainer.

[github-actions]

Test Results

  30 files  +  30    30 suites  +30   2m 38s ⏱️ + 2m 38s
207 tests +207  207 ✔️ +207  0 💤 ±0  0 ❌ ±0 
620 runs  +620  620 ✔️ +620  0 💤 ±0  0 ❌ ±0 

Results for commit a68820d. ± Comparison against base commit 9d86949.

♻️ This comment has been updated with latest results.