[Task] Create verification method

[eike-hass]

Description

Parameter: DID, Crypto Type, VerificationRelationship Returns: Fragment, Storage keyid

Motivation

Describe the motivation for the feature to be developed.

Resources

Link to any resources relevant for the task such as issues, PRs, reference implementations, or specifications.

To-do list

Create a task-specific to-do list. Please link PRs that match the TODO list item behind the item after it has been submitted.

• [ ] Item one
• [ ] Item two
• [ ] Item three

Change checklist

Add an x to the boxes that are relevant to your changes, and delete any items that are not.

• [ ] The feature or fix is implemented in Rust and across all bindings whereas possible.
• [ ] The feature or fix has sufficient testing coverage
• [ ] All tests and examples build and run locally as expected
• [ ] Every piece of code has been document according to the documentation guidelines.
• [ ] If conceptual documentation (mdbook) and examples highlighting the feature exist, they are properly updated.
• [ ] If the feature is not currently documented, a documentation task Issue has been opened to address this.