Support manual tests

[norbertlaposa]

Description

• The manual tests will be stored alongside with automated tests in the existing folder structure.
• We will use Markdown (.md) format for to distinguish from automated tests (.yaml).
• We will use rich text features such as heading, bullet point lists, etc. to make each test description readable by human.
• The workflow to be as follows:
  • User will start a new session a selects tests to include in the session.
  • The UI will allow selection in the existing tree structure with ability to additionally filter by type (automated/manual/both).
  • All automated test will be executed in the background.
  • All manual tests will require the tester manually populate the result.
  • If the manual test description includes checkboxes, all checkboxes must be ticked for the test to be considered successful.
  • If the manual test description doesn't include checkboxes, the tester must mark whole test as successful.
  • There should be a possibility to skip a manual test.
  • There should be a possibility to fail a manual test and additional comment will be required.
  • The final report should include the comments for failed tests (e.g. Email validation accepts double @ sign)

Sub tasks:

• [x] https://github.com/laposa/test-portal/issues/80
• [x] #88