feat: agent configuration and minor tweaks

Added agent configuration options on start
- User can opt to not add AgentStartConfiguration object on start call for default settings
- Default settings are all true, log level info, and default collector addresses
Removed Console.WriteLine(...) from debugging
Added default HttpClientManager to iOS since it will automatically instrument out of the box
Added SetPlatformVersion to iOS binding and added set platform version on Start

newrelic / newrelic-maui-plugin