Enhancement: In Portable Mode, Make `Program` Plugin Cache Files Computer-Specific to Support Syncing Portable Installations Across Multiple Computers (eg, via OneDrive)

Implementing this request would help somewhat with #2684. I sync my portable installation via OneDrive, and I currently have a [custom script](https://github.com/Flow-Launcher/Flow.Launcher/issues/2684#issuecomment-2539043112) that deletes `\UserData\Cache\UWP.cache` and `\UserData\Cache\Win32.cache` every time I unlock my computer so that Flow will rebuild the cache based on the current computer.

@onesounds Has created a Recently Used plugin (for which I am very grateful!) and very cleverly made the caching [machine-specific](https://github.com/Flow-Launcher/Flow.Launcher/issues/2560#issuecomment-3047752230), in the form of `cache_COMPUTERNAME.json`.

So taking inspiration from that, my request/proposal is that if Flow knows it is being used in Portable Mode, that the `Program` plugin cache files be computer-specific, similar to the following examples:
`\UserData\Cache\UWP_FIRSTCOMPUTERNAME.cache`
`\UserData\Cache\Win32_FIRSTCOMPUTERNAME.cache`
`\UserData\Cache\UWP_SECONDCOMPUTERNAME.cache`
`\UserData\Cache\Win32_SECONDCOMPUTERNAME.cache`

Thank you in advance for considering this request! 😊