Change list

The NewAppiumSessionPayload is very hacky and also hard to read. It basically copies the most of NewSessionPayload Selenium class while adding some specific workarounds on top of that. The idea is to get rid of it and use the original implementation from Selenium as we don't want or need to do jwp->w3c conversion anymore. Also removed the obsolete FORCE_MJSONWP capability.

Types of changes

• No changes in production code.
• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)