New "Warning" Log Level

[clari7744]

I propose to add a "warning" log level.

https://github.com/simulot/immich-go/blob/35982819550c81ab615424cc10dd710d455e9952/helpers/fileevent/fileevents.go#L51C1-L76C2

There are a number of log events found here that, while not being errors, may merit more attention than a simple Info log. Therefore, adding a mid-level log level such as Warning would be helpful for looking through the logs. A proposed heuristic for the log level is as such:

• A successful message (uploaded, scanned, added to album) should remain Info
  • "Server has same" is probably fine here as well
• A problem that is handled (discarded, unsupported, missing metadata, duplicate in input, file not selected) should become a Warning, so they can be looked at more thoroughly by the end user and determined whether it's a problem or not
• And of course, proper errors (failed to upload, failed to scan etc) should remain as Error
  To be precise, here is what I recommend for the existing log types:

var _code = map[Code]string{
	DiscoveredImage:       "scanned image file", // info
	DiscoveredVideo:       "scanned video file", // info
	DiscoveredSidecar:     "scanned sidecar file", // info
	DiscoveredDiscarded:   "discarded file", // WARNING
	DiscoveredUnsupported: "unsupported file", // WARNING

	AnalysisAssociatedMetadata:        "associated metadata file", // info
	AnalysisMissingAssociatedMetadata: "missing associated metadata file", // WARNING
	AnalysisLocalDuplicate:            "file duplicated in the input", // WARNING

	UploadNotSelected:     "file not selected", // WARNING
	UploadUpgraded:        "server's asset upgraded with the input", // warning/info; up for debate
	UploadAddToAlbum:      "added to an album", // info
	UploadServerDuplicate: "server has same asset", // info
	UploadServerBetter:    "server has a better asset", // warning/info; up for debate
	UploadAlbumCreated:    "album created/updated", // info
	UploadServerError:     "upload error", // error
	Uploaded:              "uploaded", // info

	Stacked:   "Stacked",
	LivePhoto: "Live photo",
	Metadata:  "Metadata files",
	Info:      "Info",
	Warning:   "Warning"
	Error:     "Error",
}

[simulot]

Thank you.