[mod] use ask key for display_text instead and support i18n

[Psycojoker]

The problem

While working on the admin integration I realized that uniformizing the behavior with other key and using "ask" instead of "text" was way simpler for the whole code (despite not making that much sens for "display_text" field) and annex tool (i18n integration for example).

I also added i18n support.

PR Status

Ready to merge.

How to test

Use this app and try to install it https://github.com/Psycojoker/display_text_ynh

Validation

• Principle agreement 0/2 :
• Quick review 0/1 :
• Simple test 0/1 :
• Deep review 0/1 :

[alexAubin]

smol change, yolomergin'

[Psycojoker]

@YunoHost/apps just to inform you about the final format ^

[maniackcrudelis]

Final format of that #669, I guess ?

So it would be that: ?

{
    "name": "some_text",
    "type": "display_text",
    "ask": "This is some text that is going to be displayed.\n\nAnother line."
},

With ask instead of text

[Psycojoker]

Nearly: https://github.com/Psycojoker/display_text_ynh/blob/master/manifest.json#L47-L52 (translation is integrated)