[FEATURE] Add cache path as a BetterPlayerCacheConfiguration parameter

[A-Ghattas]

Is your feature request related to a problem? Please describe.
I have a use case where the app users do not have cheap access to internet, so it's crucial to have the video persist unless the user delete the app or specifically delete the cache files. The best solution I found to keep the "streaming UX" instead of downloading the videos then watch them is to change the path to somewhere outside of the temporary folder as proposed in this stackoverflow thread:
https://stackoverflow.com/questions/42273350/any-option-to-restrict-our-android-application-cache-being-cleared

Describe the solution you'd like
I want an attribute path added to the BetterPlayerCacheConfiguration

Describe alternatives you've considered
If anyone have an alternative solution to my initial problem, keeping the video persistent on the device. Please let me know.
For now, the only alternative I have is to download the videos and then play them in betterplayer from the local file, that will change the UX and my client refuses that.

Additional context
Nothing else, Thank you.