Delete or warn user about locally stored crashdumps

[Broxzier]

In #3417 it's mentioned that the amount of crash dumps can take up quite some disk space. Now that #15101 is merged and crash dumps are nicely contained in a separate folder, this should be more straight-forward to implement.

Some options:

• Automatically remove all crash dumps on game boot
• Automatically remove crash dumps older than a set amount of time
• Automatically remove crash dumps when folder exceeds a set size limit or number of dumps limit (like autosaves)
• Warn user when the total space exceeds a set size limit or number of crash dumps
  • Provide a way to let the game clear them

Just like with the 'autosave' folder, players aren't supposed to use the 'crash' folder to store their parks. There are situations where a player wishes to restore (parts of) their park though, and require the save file for this even if it's corrupt. I think the least amount of work while still considering a player's lost work would be to only remove old dumps without warning.

[duncanspumpkin]

Option 3 delete oldest after a certain amount would be the most sensible in my opinion.

[ZehMatt]

It might be also good to tag the saves as actual autosaves in NSF, like most of the games do it.