feat: Add missing mod.ts files in std (#3509)

std/archive/tar.ts:
- Remove FileReader.
- Remove FileWriter.

std/encoding/csv.ts:
- ExtendedParseOptions -> ParseOptions
- HeaderOption -> HeaderOptions
- ParseOptions -> ReadOptions
- readAll() -> readMatrix()

std/encoding/yaml.ts:
- DumpOptions -> StringifyOptions

std/fmt/colors.ts:
- getEnabled() -> getColorEnabled()
- setEnabled() -> setColorEnabled()

std/testing/mod.ts:
- Re-export sibling modules.

std/testing/mod.ts

@@ -1,5 +1,12 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 
+export * from "./asserts.ts";
+export * from "./bench.ts";
+import diff from "./diff.ts";
+export { diff };
+export * from "./format.ts";
+export * from "./runner.ts";
+
 import {
   bgRed,
   white,