Enabled skip-integrity-check flag for install command

[bestander]

Summary

Sometimes you need to run full install even if integrity check returns OK.

Test plan

1. Added unit tests

2. manual test for skip and forece

# git clone react-native
yarn install
echo -e "# yolo\n$(cat yarn.lock)" > yarn.lock
rm -rf node_modules/chalk

yarn install
# install skipped

yarn install --skip-integrity-check
ls node_modules/chalk
head yarn.lock
# check that yarn.lock kept the comment

yarn install --force
head yarn.lock
# check that yarn.lock removed the comment

• change a version in package.json
• run yarn install --frozen-lockfile
• get Your lockfile needs to be updated, but yarn was run with --frozen-lockfile.