Improve message for error "incompatible properties"

[mikeharder]

The message for error "incompatible properties" only includes the key:

openapi-diff/src/lib/util/resolveSwagger.ts

Lines 247 to 249 in a813782

	if (!this.isEqual(allOfSchema.properties[key], schemaList[key])) {
	throw new Error(`incompatible properties : ${key} `)
	}

This can make it hard to determine the problem in the spec, especially if the incompatible property is being pulled in through allOf. For example:

Azure/azure-sdk-tools#7917

This error could be improved by:

1. Include the incompatible properties themselves in the error message
2. Include line numbers of the incompatible properties