feat: make Sequence.all() and Sequence.any() return actual predicate values instead of booleans

Rewrite all() and any() to store and return the predicate's result directly, matching && and || semantics. Update documentation to describe the new behavior. Move tests from test/core/list/ to test/core/sequence/ and add cases verifying that the first falsey/truthy value is returned.

test/core/sequence/any.wren

@@ -0,0 +1,10 @@
+var a = [1, 2, 3]
+IO.print(a.any {|x| x > 3 }) // expect: false
+IO.print(a.any {|x| x > 1 }) // expect: true
+IO.print([].any {|x| true }) // expect: false
+
+// Returns first truthy value.
+IO.print(a.any {|x| x }) // expect: 1
+
+// Returns last falsey value.
+IO.print(a.any {|x| x < 2 ? null : false }) // expect: false