* Consistent license message for all the go files
* Fixing the last set of unconsistencies with the license headers
* Addressing PR review comments
* Fixing busy.go and busy_test.go license header
* MM-11868/MM-12010/MM-12011/MM-12036 Include dimensions for opengraph and message attachment images in post metadata
* Remove duplicate check from getFirstLinkAndImages
* Add tests for getImagesInMessageAttachments
* Rename PostMetadata.FileInfos to PostMetadata.Files
* Rename Metadata.ImageDimensions to Metadata.Images