Added improvements to merger to support additional output configuration

[jamesmcroft]

Changes have been made to incorporate the addition of the following configurable properties to the output file:

• Host, for setting the host name or IP for the API
• Base path, for setting relative to the host where the defined paths start
• Schemes, for settings the supported protocols (e.g. https)
• Security definitions, for configuring the options available for security
• Security, for configuring the specific requirements around security definitions

PR checklist

• [x] Code styling has been met on new source file changes
• [x] Contains NO breaking changes

Other information