Update CakePHP DebugKit to 3.9.3 including its sub dependencies

Changelogs summary:

 - symfony/polyfill-ctype installed in version v1.9.0
   Release notes: https://github.com/symfony/polyfill-ctype/releases/tag/v1.9.0

 - symfony/filesystem updated from v3.2.2 to v3.4.17
   See changes: symfony/filesystem@v3.2.2...v3.4.17
   Release notes: https://github.com/symfony/filesystem/releases/tag/v3.4.17

 - symfony/polyfill-mbstring updated from v1.3.0 to v1.9.0
   See changes: symfony/polyfill-mbstring@v1.3.0...v1.9.0
   Release notes: https://github.com/symfony/polyfill-mbstring/releases/tag/v1.9.0

 - symfony/debug updated from v3.2.2 to v4.1.6
   See changes: symfony/debug@v3.2.2...v4.1.6
   Release notes: https://github.com/symfony/debug/releases/tag/v4.1.6

 - symfony/console updated from v3.2.2 to v3.4.17
   See changes: symfony/console@v3.2.2...v3.4.17
   Release notes: https://github.com/symfony/console/releases/tag/v3.4.17

 - seld/jsonlint updated from 1.5.0 to 1.7.1
   See changes: Seldaek/jsonlint@1.5.0...1.7.1
   Release notes: https://github.com/Seldaek/jsonlint/releases/tag/1.7.1

 - seld/cli-prompt updated from 1.0.2 to 1.0.3
   See changes: Seldaek/cli-prompt@1.0.2...1.0.3
   Release notes: https://github.com/Seldaek/cli-prompt/releases/tag/1.0.3

 - composer/spdx-licenses updated from 1.1.5 to 1.4.0
   See changes: composer/spdx-licenses@1.1.5...1.4.0
   Release notes: https://github.com/composer/spdx-licenses/releases/tag/1.4.0

 - composer/ca-bundle updated from 1.0.6 to 1.1.3
   See changes: composer/ca-bundle@1.0.6...1.1.3
   Release notes: https://github.com/composer/ca-bundle/releases/tag/1.1.3

 - symfony/process updated from v3.2.2 to v4.1.6
   See changes: symfony/process@v3.2.2...v4.1.6
   Release notes: https://github.com/symfony/process/releases/tag/v4.1.6

 - symfony/finder updated from v3.2.2 to v4.1.6
   See changes: symfony/finder@v3.2.2...v4.1.6
   Release notes: https://github.com/symfony/finder/releases/tag/v4.1.6

 - justinrainbow/json-schema updated from 4.1.0 to 5.2.7
   See changes: jsonrainbow/json-schema@4.1.0...5.2.7
   Release notes: https://github.com/justinrainbow/json-schema/releases/tag/5.2.7

 - composer/xdebug-handler installed in version 1.3.0
   Release notes: https://github.com/composer/xdebug-handler/releases/tag/1.3.0

 - composer/composer updated from 1.3.1 to 1.7.2
   See changes: composer/composer@1.3.1...1.7.2
   Release notes: https://github.com/composer/composer/releases/tag/1.7.2

 - cakephp/debug_kit updated from 3.6.0 to 3.9.3
   See changes: cakephp/debug_kit@3.6.0...3.9.3
   Release notes: https://github.com/cakephp/debug_kit/releases/tag/3.9.3

Author: ravage84