[Tour of Beam][Task][Frontend]: Save user code

[nausharipov]

What needs to happen?

Automatically save snippets after a user edits unit example/challenge code.

Issue Priority

Priority: 3

Issue Component

Component: tour-of-beam

[github-actions]

Label awaiting cannot be managed because it does not exist in the repo. Please check your spelling.

[github-actions]

Label awaiting cannot be managed because it does not exist in the repo. Please check your spelling.

[nausharipov]

.add-labels 'new feature'

[nausharipov]

.take-issue