[DRAFT] Add documentation generation

[marioevz]

Adds the --docs flag to the hive binary, which has the following effects:

• Sets the HIVE_DOCS_MODE environment variable for the simulator container, which does the following:
  • The flag can be parsed by the hivesim library being used by (currently) all simulators and inhibit the execution of test functions that are not marked as AlwaysRun
  • The simulator will still send StartSuite, EndSuite, StartTest and EndTest requests to the hive server
• Using the TestManager, the hive server collects the test suites and test cases and then proceeds to generate a markdown document for each suite containing every single test case into the simulator folder

The following fields are added to many structures, including the TestRequest, TestSuite and TestCase:

• DisplayName: Allows specifying a different title for a test suite or test case to be displayed in the output markdown
• Category: Allows grouping together many different test cases and add sections in the markdown file

In its current state, simulators still execute each test case in full because the hivesim dependency that inhibits execution in docs mode needs to be updated once this change makes it into the master branch.

[marioevz]

Closed in favor of #948