Change Duration.toString(unit, decimals) formatting

- switch to scientific notation when value is too big (greater than 1e14)
- allow at most 12 decimals, larger values are coerced to 12
- use scientific format with exactly two decimals in mantissa in JVM

libraries/stdlib/jvm/src/kotlin/time/formatToDecimals.kt

@@ -34,4 +34,4 @@ internal actual fun formatUpToDecimals(value: Double, decimals: Int): String =
 
 private val scientificFormat = ThreadLocal<DecimalFormat>()
 internal actual fun formatScientific(value: Double): String =
-    scientificFormat.getOrSet { DecimalFormat("0E0", rootFormatSymbols).apply { maximumFractionDigits = 2 } }.format(value)
+    scientificFormat.getOrSet { DecimalFormat("0E0", rootFormatSymbols).apply { minimumFractionDigits = 2 } }.format(value)