Create new stock transaction

[horvathmarton]

New features

• add transaction create flow

Reviewer checklist

• [ ] The code functionally does what it supposed to do (implements the feature or fixes the bug).
• [ ] The code quality meets the standards.
• [ ] Tests are added to check the feature or avoid regression to a bug.
• [ ] The documentation is updated (both Postman, wiki and docstrings) if applicable.
• [ ] The logging if up to date.

references #37