Dialog synch to Gitlab

Blocked by #69

In this issue the synchronization should be tackled. Implement the design of #69 .

The dialog as multiple input fields (repo, branch and commit message)

These information should be parsed into the API call (speak with assignee of https://codebase.helmholtz.cloud/hmc/hmc/cct-1-mapping/information-portal/backend/-/issues/23 to clarify the endpoint)

Write a corresponding test for it (only if #66 ) is done.