Export statistics to .csv file

[AlexanderRitter02]

Is your feature request related to a problem? Please describe.
The statistics loss bug #490 got me thinking about stats.
For one, I'd like a way to back them up externally. Even if the bug gets fixed, that would still be important because you might switch to a new phone or lose your phone.

Additionally, an export would also allow the user to do further analysis of the games, for example the frequency of how often I play etc.
Having the data in a standard format like .csv allows to easily read it into Excel of Python.

Describe the solution you'd like
An option to export the games statistics to a .csv file.
Importing is not that important I think, but it could be added later on too.

The .csv would have each row be one game's statistics.
The columns could look sth similar to, depending on what is currently kept track of:

• date the game started
• length
• difficulty
• mine amount
• win/loss

Describe alternatives you've considered
Parsing the stats file at dev.lucanlm.antimine/files myself, but:

1. It needs root access, so not everyone can do it
2. It is in some kind of binary format because when I open it it doesn't make sense
3. I could also try implementing the export myself, but the issue with that is that even if I managed to I wouldn't be able to update the existing app and thus lose all my exisiting stats.

In general, it would just be better to have an official way.

Additional context
None