Generate Unique Username

[andrewchmr]

I solved this by:

1. Override username from string to uid in extensions/users-permissions/models/User.settings.json

“attributes”: {
“username”: {
“type”: “uid”,
“targetField”: “username”,
…

2. Generating uniq value on every registration by oveeriding extensions/users-permissions/services/Providers.js

        const uidService = strapi.plugins['content-manager'].services['uid'];

        const username = await uidService.generateUIDField({
          contentTypeUID: "plugins::users-permissions.user",
          data: { username: body.username },
          field: "username"
        });

       callback(null, {
         username,
         email: body.email,
       });