Follow OS-specific paths for installed binaries and logs instead of ~/.skiko

[62832]

Currently, Skiko always creates the $HOME/.skiko directory when used as a dependency by other projects, which can only be overridden by the skiko.data.path property. This PR does away with this directory and makes Skiko more compliant with OS-specific standards for stored program data and logs.

• On Linux-based systems (including Android), Skiko will follow the XDG Base Directory Specification and store installed binaries under $XDG_DATA_HOME/skiko and logs under $XDG_STATE_HOME/skiko, with the appropriate fallbacks if the former variables are unset. As a result, this PR closes Follow XDG Base Directory #707.
• On Windows, installed binaries and logs will be stored under %LOCALAPPDATA%/Skiko.
• On macOS and iOS, installed binaries will be stored under ~/Library/Application Support/Skiko and logs under ~/Library/Logs.

[62832]

It came to my attention at some point that the choice of following XDG paths for Android is actually incorrect. Android apparently has its own storage scheme for such data somewhere under the /data directory, but it's unclear to me what this should be for Skiko.