feat: download chrome-headless-shell by default and use it for the old headless mode

[OrKoN]

With this PR, Puppeteer will download two binaries by default: a Chrome for Testing binary and a chrome-headless-shell of the same version. chrome-headless-shell will be used as a replacement for the old headless mode.

Two new configurations are added:

1. PUPPETEER_SKIP_CHROME_DOWNLOAD to skip Chrome binary downloads (only chrome-headless-shell will be downloaded).
2. PUPPETEER_SKIP_CHROME_HEADLESS_SHELL_DOWNLOAD to skip chrome-headless-shell binary downloads (only Chrome for Testing will be downloaded).

Use these variables if you only want to use the old headless mode (chrome-headless-shell) or only the new-headless/headful mode (Chrome for Testing). The existing configuration PUPPETEER_SKIP_DOWNLOAD would still apply to both binaries.

BEGIN_COMMIT_OVERRIDE
chore: download chrome-headless-shell by default and use it for the old headless mode
END_COMMIT_OVERRIDE

[OrKoN]

@mathiasbynens I am not able to run M118 version on Mac:

 ~/.cache/puppeteer/chrome-headless-shell/mac-118.0.5993.70/chrome-headless-shell-mac-x64/chrome-headless-shell -h
[1011/201316.703505:ERROR:icu_util.cc(178)] icudtl.dat not found in bundle
[1011/201316.703923:ERROR:icu_util.cc(240)] Invalid file descriptor to ICU data received.
[1]    27079 trace trap   -h

[mathiasbynens]

Looks like this now works after the upstream packaging changes (M120+)? LGTM