[Feature] Getting Phash with a hook plugin.

[Belleyy]

Is your feature request related to a problem? Please describe.
I have a hook plugin (Scene.Create.Post) that search on stashbox when scanning file , the problem is Phash is not generate when the plugin execute. So my stashbox search only use hash and query, would be more accurate with Phash.

Describe the solution you'd like

1. Made a option to generate the Phash in same time as Ohash instead of being a separate operation.
2. Made a new operation just to calculate the Phash and return it.
3. Change the order of generate/hook.

• Current: Scan > Hook Plugin > Generate
• New: Scan > Generate > Hook Plugin

4. Create a new hook Scene.Create.Post.Generate (Only when you do generate during scan not generate alone)

Describe alternatives you've considered
Made the operation MetadataGenerate without queue. If a plugin try to send this operation, stash will put it in the Job queue so using this operation in a plugin is useless. Would be better if a plugin send this operation it should be execute directly.