Move errors out of the utility package

...github.com/turt2live/matrix-media-repo/api/r0/download.go

src/github.com/turt2live/matrix-media-repo/api/r0/info.go

...thub.com/turt2live/matrix-media-repo/api/r0/local_copy.go

...hub.com/turt2live/matrix-media-repo/api/r0/preview_url.go

...ithub.com/turt2live/matrix-media-repo/api/r0/thumbnail.go

src/github.com/turt2live/matrix-media-repo/api/r0/upload.go

...thub.com/turt2live/matrix-media-repo/common/errorcodes.go

src/github.com/turt2live/matrix-media-repo/common/errors.go

...om/turt2live/matrix-media-repo/media_cache/media_cache.go

...urt2live/matrix-media-repo/media_cache/thumbnail_cache.go

...matrix-media-repo/services/media_service/media_service.go

...ia-repo/services/media_service/remote_media_downloader.go

...edia-repo/services/thumbnail_service/thumbnail_service.go

.../matrix-media-repo/services/url_service/file_previewer.go

...ix-media-repo/services/url_service/opengraph_previewer.go

...atrix-media-repo/services/url_service/resource_handler.go

...ive/matrix-media-repo/services/url_service/url_service.go