Layout and styling for transfer-project-ownership

[jamesrkiger]

Checklist

1. If you've added code that should be tested, add tests
2. If you've changed APIs, update (or create!) the documentation
3. Ensure the tests pass
4. Make sure that your code lints and that you've followed our coding style
5. Write a title and, if necessary, a description of your work suitable for publishing in our release notes
6. Mention any related issues in this repository (as #ISSUE) and in other repositories (as kobotoolbox/other#ISSUE)
7. Open an issue in the docs if there are UI/UX changes

Description

Updates layout and styling for transfer-project-ownership feature to match designs.

Notes

The spacing between the label and the input box in the modal textbox does not match the design, as this spacing is set in the reusable textbox component. The same goes for the the thickness of the lines/font in the framed buttons. I figured those discrepancies should be addressed separately with an eye to making sure other parts of the app look right.