[FIX] pos_display_*: refactor to show extra info only in Product screen

[trisdoan]

This change

• Before this commit, extra info were shown on Receipt,... which is prohibited in some countries
• Beside, template customization was not versatile (replace standard with a wrapper div), comparing to new approach:
  • Take advantage of t-set-slot='details' from standard to add extra info
  • Ensure the extra info is displayed on Product screen, not Receipt/Ticket/Customer display
  • Side-effect: don't need to add usePos service

Result

Before

After

Receipt

[OCA-git-bot]

Hi @henrybackman,
some modules you are maintaining are being modified, check this out!

[sebduch73]

Hello.
I have test the modules and it's ok.
@ivantodorovich can you validate the PR to OCA ? thx a lot

[ivantodorovich]

Looks good ! Thanks!