Use XDG base directories and Known Folders on Windows (#1809)

This changes logic that previously read/wrote from `~/.pkl` to use
XDG base directories (all OSes), and Known Folders locations on Windows.

For example, Pkl will look for `settings.pkl` in:

1. `$XDG_CONFIG_HOME/pkl/settings.pkl`
2. `%APPDATA/pkl/settings.pkl`
3. `~/.pkl/settings.pkl`
4. Path pkl/settings/pkl within `$XDG_CONFIG_DIRS`
5. `/etc/xdg/pkl/settings.pkl`

---------

Co-authored-by: Florin Ungur <florin@florinungur.com>

pkl-cli/src/main/kotlin/org/pkl/cli/repl/Repl.kt

@@ -63,7 +63,11 @@ internal class Repl(workingDir: Path, private val server: ReplServer, private va
         }
         completer(AggregateCompleter(CommandCompleter, FileCompleter(workingDir)))
         option(Option.DISABLE_EVENT_EXPANSION, true)
-        variable(LineReader.HISTORY_FILE, (IoUtils.getPklHomeDir().resolve("repl-history")))
+        // Will be null if `user.home` property is not set.
+        // If so, don't bother writing repl history.
+        IoUtils.getReplHistoryFile()?.let { historyFile ->
+          variable(LineReader.HISTORY_FILE, historyFile)
+        }
       }
       .build()
 
@@ -80,7 +84,7 @@ internal class Repl(workingDir: Path, private val server: ReplServer, private va
 
   fun run() {
     // JLine 2 history file is incompatible with JLine 3
-    IoUtils.getPklHomeDir().resolve("repl-history.bin").deleteIfExists()
+    IoUtils.getLegacyPklHomeDir().resolve("repl-history.bin").deleteIfExists()
 
     println(ReplMessages.welcome)
     println()