infra coding_style: Add coding style check bot

Add a bot that checks the coding style using cpplint
and reports the result as a review comment.

This feature refers to the repository where cpplint
and docker settings with github-action.
This action works whenever a PR is created and updated.

In cpplint, only the violation of ThorVG's coding style is reported
as a warning using several options.
whitespace/parens
whitespace/indent
whitespace/end_of_line
whitespace/blank_line

The bot will review all of the contents of all files in the current commit file list,
However, in the future, we will improve Bot to only review the changes.

.github/workflows/actions_cpplint.yml

@@ -0,0 +1,33 @@
+name: PullRequest_Checker
+
+on:
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: true
+
+    - name: Install Packages
+      run: |
+        sudo apt-get update
+        sudo apt-get install curl
+        sudo apt-get install cmake jq clang
+        sudo apt-get install software-properties-common
+        sudo apt-get install python3-pip
+        pip3 install wheel --user
+        pip3 install cpplint --user
+
+    - name: Run Cpplint Script
+      run: |
+        export PATH=$PATH:~/.local/bin/
+        chmod +x "${GITHUB_WORKSPACE}/.github/workflows/cpp_lint_check.sh"
+        "${GITHUB_WORKSPACE}/.github/workflows/cpp_lint_check.sh"
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+

.github/workflows/cpp_lint_check.sh

@@ -0,0 +1,59 @@
+#!/bin/bash
+
+if [[ -z "$GITHUB_TOKEN" ]]; then
+	echo "The GITHUB_TOKEN is required."
+	exit 1
+fi
+
+FILES_LINK=`jq -r '.pull_request._links.self.href' "$GITHUB_EVENT_PATH"`/files
+echo "Files = $FILES_LINK"
+
+curl $FILES_LINK > files.json
+FILES_URLS_STRING=`jq -r '.[].raw_url' files.json`
+
+readarray -t URLS <<<"$FILES_URLS_STRING"
+
+echo "File names: $URLS"
+
+mkdir files
+cd files
+for i in "${URLS[@]}"
+do
+   echo "Downloading $i"
+   curl -LOk --remote-name $i 
+done
+
+echo "Files downloaded!"
+echo "Performing checkup:"
+
+cpplint --filter=-,\
++whitespace/parens,\
++whitespace/indent,\
++whitespace/end_of_line,\
++whitespace/blank_line \
+--extension=cpp,h,c \
+--recursive \
+./ > cpp-report.txt 2>&1
+
+PAYLOAD_CPPLINT=`cat cpp-report.txt`
+COMMENTS_URL=$(cat $GITHUB_EVENT_PATH | jq -r .pull_request.comments_url)
+  
+echo $COMMENTS_URL
+echo "Cppcheck errors:"
+echo $PAYLOAD_CPPLINT
+
+if [[ $PAYLOAD_CPPLINT == *"Total errors found: "* ]]; then
+  OUTPUT+=$'\n**CODING STYLE CHECK**:\n'
+  OUTPUT+=$'\n```\n'
+  OUTPUT+="$PAYLOAD_CPPLINT"
+  OUTPUT+=$'\n```\n' 
+
+else
+  OUTPUT+=$'\n**CODING STYLE CHECK**:\n'
+  OUTPUT+=$'\n```\n'
+  OUTPUT+="Perfect."
+  OUTPUT+=$'\n```\n' 
+fi
+PAYLOAD=$(echo '{}' | jq --arg body "$OUTPUT" '.body = $body')
+
+curl -s -S -H "Authorization: token $GITHUB_TOKEN" --header "Content-Type: application/vnd.github.VERSION.text+json" --data "$PAYLOAD" "$COMMENTS_URL"