field testing revealed various bugs

[2bndy5]

I added this action to a project I'm helping develop, and I ran into some unforeseen problems. This resolves #29 , but I'll summarize the solutions here

1. Allow skipping clang-tidy when setting the option

          tidy-checks: '-*'

2. Skip fetching data from the workflow runner's event payload when setting the option

          files-changed-only: false

   This helps run the python pkg locally as a CLI tool instead of only as a Github action.
3. Ignore hidden directories that aren't in the repo's root directory. For exmaple, .github was being ignored, but a sub-directory like src/.hidden was not being ignored.
4. Augment get_line_cnt_from_cols() to better support CRLF & LF line endings by opening the source file as a binary file. This might also address different encoded source files (anything that isn't utf-8).
5. Prevent creating a bogus clang-format notification when clang-format did not report any problems or fixes. Previously, XML metadata was triggering a clang-format notification when there was no actual fixes from clang-format.
6. Enhance parsing clang-tidy notifications using pure regexp matching. Previously, a crashing error would occur when the notification contained : in the description. For example:

   /src/main.cpp:221:1: warning: do not declare C-style arrays, use std::array<> instead [cppcoreguidelines-avoid-c-arrays,modernize-avoid-c-arrays]
   bool         FailSafeChannel[17];
   ^
   

   The phrase std::array would previously cause a parsing error because I was using str.split(":") to parse the notification.

This can now be run as a standalone CLI tool

For better usage as a CLI tool, I've renamed the python pkg from python_action to cpp_linter. Once installed, it can be executed anywhere by running

cpp-linter -h

Furthermore, I changed some of the default values for the CLI args to check all files in the current working directory and disabling thread comments. These changes are overridden by the default values for options in the action.yml, so behaviorally, there are no changes to defaults when executing cpp-linter as a github action.

Also, I added pyyaml back in as dependency when installing locally. This should not slow down the setup time as pyyaml is already installed in the docker image we use as an action, but pyyaml may not be installed locally when used as a CLI tool.

[shenxianpeng]

Look good to me.