LibJS: Begin using CalendarMethodsRecord for AOs

This begins the process of aligning our implementation with the spec
with regard to using CalendarMethodsRecord. The main intent here is to
make it much easier to make normative changes to AOs which have been
updated to CalendarMethodsRecord.

While this does resolve various FIXMEs, many others above need to be
added in order to be able to pass through a CalendarMethodsRecord. The
use here aligns with what I can gather from the spec of what the
arguments to CreateCalendarMethodsRecord should be, but various AOs have
been updated so much with other changes it's not completely obvious.
Other AOs do not even exist in the latest version of the spec, but we
still rely on them.

As part of these updates, this commit coincidentally also fixes two
PlainDate roundingmode issues seen in test262 - a test of which is also
added in test-js. This issue boiled down to what appears to be an
observable optimization in the spec, where it can avoid calling
dateUntil in certain situations (roundingGranularityIsNoop).

However, the main goal here is to make it much easier to fix many more
issues in the future :^)

since/calendar-dateuntil-called-with-singular-largestunit.js ❌ -> ✅
until/calendar-dateuntil-called-with-singular-largestunit.js ❌ -> ✅

Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainDate/PlainDate.prototype.since.js

@@ -258,4 +258,29 @@ describe("errors", () => {
             }
         }
     });
+
+    test("dateUntil only called once with rounding mode of days and small enough granularity", () => {
+        const actual = [];
+
+        class DateUntilOptionsCalendar extends Temporal.Calendar {
+            constructor() {
+                super("iso8601");
+            }
+
+            dateUntil(earlier, later, options) {
+                actual.push(options.largestUnit);
+                return super.dateUntil(earlier, later, options);
+            }
+        }
+
+        const calendar = new DateUntilOptionsCalendar();
+
+        largestUnit = "days";
+        expected = [];
+
+        const earlier = new Temporal.PlainDate(2000, 5, 2, calendar);
+        const later = new Temporal.PlainDate(2001, 6, 3, calendar);
+        later.since(earlier, { largestUnit });
+        expect(actual).toEqual([]);
+    });
 });