[Lint] Improve clang-tidy and clang-format scripts running in lint

[mwtian]

This partially rolls forward commit 5d9e3a0, except changes to
scripts/format.h

Why are these changes needed?

• Add more readability checks to clang-tidy
• Disable modernize-use-nodiscard which is too pedantic.
• On a branch just forked off master, diff against the current commit instead of the previous commit if there is local change for both clang-tidy and clang-format.
• Make status messages stand out more in clang-tidy and clang-format.

These changes do not affect scripts/format.sh. These scripts currently only run during the lint step of the CI.

Related issue number

Checks

• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
  • Release tests
  • This PR is not tested :(

[mwtian]

The rllib failure is unrelated. It is fixed by bbc64a7.

[scv119]

@mwtian Does it make sense to separate it into two PRs to make it easier to get in? I.e. one just changing linter rules another change the the ci/travis/check-git-clang-format-output.sh ?

[mwtian]

Sure, broke out clang-tidy rule changes to #19210.

[bveeramani]

‼️ ACTION REQUIRED ‼️

We've switched our code formatter from YAPF to Black (see #21311).

To prevent issues with merging your code, here's what you'll need to do:

1. Install Black

pip install -I black==21.12b0

2. Format changed files with Black

curl -o format-changed.sh https://gist.githubusercontent.com/bveeramani/42ef0e9e387b755a8a735b084af976f2/raw/7631276790765d555c423b8db2b679fd957b984a/format-changed.sh
chmod +x ./format-changed.sh
./format-changed.sh
rm format-changed.sh

3. Commit your changes.

git add --all
git commit -m "Format Python code with Black"

4. Merge master into your branch.

git pull upstream master

5. Resolve merge conflicts (if necessary).

After running these steps, you'll have the updated format.sh.

[stale]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

• If you'd like to keep this open, just leave any comment, and the stale label will be removed.

[stale]

Hi again! The issue will be closed because there has been no more activity in the 14 days since the last message.

Please feel free to reopen or open a new issue if you'd still like it to be addressed.

Again, you can always ask for help on our discussion forum or Ray's public slack channel.

Thanks again for opening the issue!