[Start] Build histogram for click rates of Home button on NTP

In this CL, we completed the histogram "NewTabPage.Module.Click" by recording the clicking actions on the home button on New Tab Page and adding the test for it. The histogram is recorded when the user clicks on the home button.
We also created a new histogram "NewTabPage.HomeButtonLongClick" to record the clicking actions on the home button in New Tab Page when user long presses on home button to edit homepage.
In order for readability, we made a google sheet to summarize the behavior of the UMA histograms for clicking actions on Home button in NTP: https://docs.google.com/spreadsheets/d/1B1K1Jk6-14k6xfmodnTWYrrKdjpSY022XdUDuJO6JQU/edit?usp=sharing

Change-Id: Iabd51cae5e8246bfcee0d7c096c55c2435eaeb19
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4374344
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Patrick Noland <pnoland@chromium.org>
Reviewed-by: Xi Han <hanxi@chromium.org>
Commit-Queue: Xinyi Ji <xinyiji@chromium.org>
Reviewed-by: Weilun Shi <sweilun@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1125383}