Enhanced long-text preview and title line settings, along with improved image and file content handling.

[nicoxb]

Note: I'm a developer, but not a macOS developer. I submitted this entirely out of my love for Maccy, and all the code was written by AI — I only provided the ideas and verification. If you prefer not to merge AI-generated code, please feel free to ignore this PR. However, I do hope these additions and improvements can make it into the project when you have the time.

Features:

1. fix: Previewing two adjacent image contents does not switch the slide out preview content.
2. feat: add button to save image content to 'Pictures' folder.
3. feat: add button to locate file content.
4. feat: add title lines setting and improve title truncation in history item views.
5. feat: optimize long-text handling in HistoryItemDecorator and improve display in PreviewItemView.

Preview multi line in the title:

Configurable title lines:

Save image content to file:

Locate to files: