github-ci: fix commit message for markdown

Found that commit message may consists of special characters which can
be used be Markdown as commands, like '`' or '```'. To avoid of it these
characters must be changed to some predefined names like for:

'\' - BACKSLASH
'`' - BACKTICK

Also added filter block to avoid of other not known symbols which we
could miss. This block converts commit message to HTML and then takes
only text from it.

Author: avtikhon

.github/actions/send-telegram-notify/action.yml

@@ -42,6 +42,49 @@ runs:
         curl -s https://api.github.com/repos/tarantool/tarantool/actions/runs/${{ github.run_id }}/jobs | jq -r '.jobs[0].id' | tee -a $GITHUB_ENV
         echo 'EOF' >> $GITHUB_ENV
       shell: bash
+    # convert commit message to single line with marked new lines as 'TELEGRAMNEWLINE'
+    - env:
+        COMMIT_MSG: |
+          ${{ github.event.head_commit.message }}
+      run: |
+        # Make changes in the commit message to avoid of its fail on Markdown:
+        # 1. Convert message from multi lines to single line.
+        # 2. Add backslashes to single quote marks in message.
+        # 3. Add backslashes to '`' in message.
+        if ${{ env.OS_IS_FEDORA_OR_RHEL == 'true' }} || ${{ env.KERNEL_NAME == 'Darwin' }} ; then
+          msg="${COMMIT_MSG//$'\n'/TELEGRAMNEWLINE}"
+          msg="${msg//$'\\\\'/BACKSLASH}"
+          msg="${msg//$'\\\''/\'}"
+          msg="${msg//$'\`'/BACKTICK}"
+        else
+          msg="${COMMIT_MSG//$'\n'/TELEGRAMNEWLINE}"
+          msg="${msg//$'\\'/BACKSLASH}"
+          msg="${msg//$'\''/\\\'}"
+          msg="${msg//$'`'/BACKTICK}"
+        fi
+        echo 'COMMIT_MSG_LINE<<EOF' >> $GITHUB_ENV
+        echo "$msg" | tee -a $GITHUB_ENV
+        echo 'EOF' >> $GITHUB_ENV
+      shell: bash
+    # strip Markdown from commit message
+    - run: |
+        pip3 install setuptools
+        pip3 install markdown bs4
+        echo "Sending commit message part as a single line: ${{ env.COMMIT_MSG_LINE }}"
+        msg=`python3 -c "import markdown ; \\
+          from bs4 import BeautifulSoup ; \\
+          md = markdown.markdown(\"${{ env.COMMIT_MSG_LINE }}\") ; \\
+          soup = BeautifulSoup(md, features='html.parser') ; \\
+          print(soup.get_text())"`
+        echo "Sending commit message part as a single line: $msg"
+        echo 'COMMIT_MSG<<EOF' >> $GITHUB_ENV
+          if ${{ env.OS_IS_FEDORA_OR_RHEL == 'true' }} || ${{ env.KERNEL_NAME == 'Darwin' }} ; then
+            echo $msg | sed "s#TELEGRAMNEWLINE#\\\n#g" | tee -a $GITHUB_ENV
+          else
+            echo $msg | sed "s#TELEGRAMNEWLINE#\n#g" | tee -a $GITHUB_ENV
+          fi
+        echo 'EOF' >> $GITHUB_ENV
+      shell: bash
     - env:
         MSG: |
           🔴 Workflow testing failed:
@@ -54,7 +97,7 @@ runs:
           Committer: `${{ github.actor }}`
           ```
           ---------------- Commit message -------------------
-          ${{ github.event.head_commit.message }}
+          ${{ env.COMMIT_MSG }}
           ```
       run: |
         # convert message from multi lines to single line and