Allow more customizations when translating

[sargreal]

Currently, the default translation behavior of DeepL is used. However, it supports many additional options that should be provided to the user when starting a translation (directly or batch).

The relevant options are:

• split_sentences
• preserve_formatting
• formality: default, prefer_more or prefer_less
• glossary_id: glossary to use for this translation

Following things need to be done:

• Allow setting defaults for these values through the configuration (or the admin panel, see Configuration of plugin options also through admin #23)
• Configure router and service to handle these options
• Configure translation modals to allow setting these options