Fixes OpenAPI PowerShell 5.1 compatibility issue while testing schemas; Fixes OpenAPI DefinitionTag being null in some functions; Changes "-ContentMediaType" and "-MediaType" parameters to "-ContentType" on most OpenAPI functions; Ensures the generated OpenAPI document now maintains element ordering

Fixes OpenAPI PowerShell 5.1 compatibility issue while testing schemas; Fixes OpenAPI DefinitionTag being null in some functions; Changes "-ContentMediaType" and "-MediaType" parameters to "-ContentType" on most OpenAPI functions; Ensures the generated OpenAPI document now maintains element ordering #754