Update Admin Toolbar module from ~2.0 to ~3.0

Problem/Motivation

Admin Toolbar 3.0.2 was released 25 Aug 2021 at 12:11 EEST
https://www.drupal.org/project/admin_toolbar/releases/3.0.2

Admin Toolbar - Moderately critical - Cross Site Scripting, Access Bypass - SA-CONTRIB-2021-025

And Not supported! Admin Toolbar 8.x-2.5

Security update:3.0.2 (2021-Aug-25)

Steps to reproduce

Proposed resolution

Update to ~3.0 on the varbase_core 8.x-8.x branch

Remaining tasks

• Update
• Test
• Review
• Quick Release

User interface changes

• None

API changes

• None

Data model changes

• None