Release 8.2.8

Problem/Motivation

Release Thunder 8.2.8

Remaining tasks

Multiple pull requests have to be created to prepare the release.

PR1: Create release preparation branch from master, merge develop into it. Fix merge conflicts, these will occur because of build-thunder.make files. Keep the old version in the build-thunder.make files. Merge into master without squashing.

PR2: Create release branch from master, create two commits, one to bump version in build-thunder.make files and a second one to write the changelog. Merge back into master without squashing. Now tag master branch (The semantic version 8.2.8 as well as the drupal "semantic" version 8.x-2.8) and push the new tags to origin. After tags are pushed, create release on drupal.org.

PR3: Create branch from develop, cherry pick the changelog commit from master. Merge back to develop without squashing.