This CL moves cctest/parsing/{test-parse-decision,
test-scanner-streams, test-scanner} to unittests/{
parse-decision-unittest, scanner-streams-unittest,
scanner-unittest}.

Bug: v8:12781
Change-Id: I2adfeaf2ccc796f17d6b7010c77b1f65c6ce593e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3612668
Commit-Queue: 王澳 <wangao.james@bytedance.com>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80588}