…nsion

Direct PHP API Client package dependency is now replaced with
the indirect dependency using `web-vision/deeplcom-deepl-php`
as shared extension allowing to have more then one extension
released in TER requiring that dependency and bundling client
package for TER uploade is removed along the way.

Used command(s):

```shell
BIN_COMPOSER="$(which composer)" && \
${BIN_COMPOSER} remove --no-update \
  'deeplcom/deepl-php' && \
${BIN_COMPOSER} require --no-update \
  'web-vision/deeplcom-deepl-php':'^1.12.0'
```