Fix formatting of argument lists (#1283)

This fixes several issues:

1. Leading/trailing line comments surrounding a lambda should make that
   lambda not "trailing", because the formatting otherwise looks bad and
   also isn't stable
2. Fix incorrect algorithm for detecting trailing lambda (currently,
   any number of lambdas makes the alg return `true`)

pkl-formatter/src/test/files/FormatterSnippetTests/input/method-call-trailing-lambdas.pkl

@@ -19,3 +19,27 @@ res4 = foo.foldLeft(
 res5 = ifNonNull((it) -> someFunctionCall(it as SomeReaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaalyLongTypeName))
 
 res6 = ifNonNull((it) -> someFunctionCall(it as SomeReaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaalyLongTypeNameLonger))
+
+res7 =
+  qux(bar, (a) ->
+    hello // some comment
+  )
+
+res8 = qux(
+  // some comment
+  (a) -> bar
+)
+
+res9 =
+  qux(bar, new {
+    bar = 1
+  } // some comment
+  )
+
+res10 = (a) -> hello // some comment
+
+res11 =
+  qux(bar, (a) ->
+    hello
+    // some comment
+  )

pkl-formatter/src/test/files/FormatterSnippetTests/output/line-breaks.pkl

@@ -76,8 +76,9 @@ local function render(currentIndent: String) =
 
 items: List<Item> =
   allItems
-    .filter((item) ->
-      badItems.containsKey(item) // some line comment 
-        || item.tags.toList().findOrNull((it) -> it.type == "bookmark") != null // some other line comment
+    .filter(
+      (item) ->
+        badItems.containsKey(item) // some line comment 
+          || item.tags.toList().findOrNull((it) -> it.type == "bookmark") != null // some other line comment
     )
     .sortBy((item) -> item.name)

pkl-formatter/src/test/files/FormatterSnippetTests/output/method-call-trailing-lambdas.pkl

@@ -25,3 +25,32 @@ res6 =
   ifNonNull((it) ->
     someFunctionCall(it as SomeReaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaalyLongTypeNameLonger)
   )
+
+res7 =
+  qux(
+    bar,
+    (a) -> hello // some comment
+  )
+
+res8 =
+  qux(
+    // some comment
+    (a) -> bar,
+  )
+
+res9 =
+  qux(
+    bar,
+    new {
+      bar = 1
+    } // some comment
+  )
+
+res10 = (a) -> hello // some comment
+
+res11 =
+  qux(
+    bar,
+    (a) -> hello
+    // some comment
+  )