Add user profile view

[IvanStepanok]

Added screen of another user profile, with an option to open it from the discussion screen.
Full name and year of birth are displayed only for staff members.

Below are scenarios of what a profile might look like:

Learner viewing user profile without bio

Learner viewing user profile with bio

Staff user viewing user profile with bio

[marcotuts]

No product or design suggestions or feedback! 🔥

[openedx-webhooks]

Thanks for the pull request, @IvanStepanok! Please note that it may take us up to several weeks or months to complete a review and merge your PR.

Feel free to add as much of the following information to the ticket as you can:

• supporting documentation
• Open edX discussion forum threads
• timeline information ("this must be merged by XX date", and why that is)
• partner information ("this is a course on edx.org")
• any other information that can help Product understand the context for the PR

All technical communication about the code itself will be done via the GitHub pull request interface. As a reminder, our process documentation is here.

Please let us know once your PR is ready for our review and all tests are green.

[openedx-webhooks]

@IvanStepanok 🎉 Your pull request was merged! Please take a moment to answer a two question survey so we can improve your experience in the future.