Fix the issues reported by phpcs

Problem/Motivation

FILE: ...cont/discord_webform_handler/src/Plugin/WebformHandler/DiscordWebformHandler.php
--------------------------------------------------------------------------------------
FOUND 4 ERRORS AND 1 WARNING AFFECTING 5 LINES
--------------------------------------------------------------------------------------
1 | ERROR | [x] The PHP open tag must be followed by exactly one blank line
24 | ERROR | [x] Expected 1 blank line before function; 0 found
59 | WARNING | [ ] Unused variable $response.
64 | ERROR | [x] Expected newline after closing brace
69 | ERROR | [x] Expected 1 newline at end of file; 0 found
--------------------------------------------------------------------------------------
PHPCBF CAN FIX THE 4 MARKED SNIFF VIOLATIONS AUTOMATICALLY
--------------------------------------------------------------------------------------

FILE: /var/www/html/vb/d_cont/discord_webform_handler/discord_webform_handler.module
------------------------------------------------------------------------------------
FOUND 2 ERRORS AFFECTING 1 LINE
------------------------------------------------------------------------------------
1 | ERROR | [x] Missing file doc comment
1 | ERROR | [x] Expected 1 newline at end of file; 0 found
------------------------------------------------------------------------------------
PHPCBF CAN FIX THE 2 MARKED SNIFF VIOLATIONS AUTOMATICALLY
------------------------------------------------------------------------------------

FILE: /var/www/html/vb/d_cont/discord_webform_handler/discord_webform_handler.info.yml
--------------------------------------------------------------------------------------
FOUND 1 ERROR AND 1 WARNING AFFECTING 1 LINE
--------------------------------------------------------------------------------------
7 | WARNING | [ ] All dependencies must be prefixed with the project name, for
| | example "drupal:"
7 | ERROR | [x] Expected 1 newline at end of file; 0 found
--------------------------------------------------------------------------------------
PHPCBF CAN FIX THE 1 MARKED SNIFF VIOLATIONS AUTOMATICALLY
--------------------------------------------------------------------------------------

Time: 58ms; Memory: 10MB

Steps to reproduce

Execute the command: phpcs --standard=Drupal,DrupalPractice --extensions=php,module,inc,install,test,profile,theme,css,info,txt,md,yml,twig discord_webform_handler/

Remaining tasks

Patch review