Feature: Add selection form profile avatar from certain list

[ReDBrother]

Battle.net have custom list of avatar which users can choose

Backend: Add new prop "current_profile_avatar_url" for user model and api for update and retrieve list of available avatars and their avatars from discord/github if they link external profiles

Frontend: Add new internal page for user profile with list of available avatars. Especially show github/discord avatars if needs
And highlights chosen avatar on list.

Page Schema:

Show avatar on other pages (game preview, custom tournaments) by "current_profile_avatar_url" or according to the logic already written (it will be a default)

[GoldDrakon]

Summary:
There is no way to change the profile avatar.
Environment:
System:Windows 10 64-bit
Opera version Chromium:131.0.6778.266
Google Chrome version 133.0.6943.99 (Official build), (64 bit)
Firefox Windows MSIX package mozilla-MSIX-1.0 version 136.0 (64-bit)
Steps-to-reproduce:
1. Click Nickname
2. Go to "My profile"
3. Click to avatar
Expected-result:
You can select an avatar from a specific list.
Actual-result:
Nothing happens.
Current version: b6f5da5

[Michael57e]

Summary:
No function to change user`s avatar

Environment:
Chromium 135.0.7049.84 (Official Build) snap (64-bit)
OS Ubuntu 24.04.2 LTS

Steps-to-reproduce:

1. Open the page
2. Click user`s avatar
3. Click Settings
4. Click Edit
5. Choose image

Expected-result:
Function to change user`s avatar picture is available

Actual-result:
No function to change avatar`s picture