Add WiiLink File Clearer

[hwalker56]

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WiiLink File Clearer is a new app to let users delete various WiiConnect24 related files to fix issues in channels.
This pull request also removes the old RC24 Clear Tool, as it contains unsafe functionality (namely SYSCONF deletion), which can lead to bricks. This app is obsoleted by the WiiLink File Clearer, and should no longer be used.

[Artuto]

The app should be flagged with writes_to_nand