feat!: move rdimitrov/go-tuf-metadata to github.com/theupdateframework/go-tuf/v2

[rdimitrov]

Description:

The following PR replaces the content of the existing master branch with the content of the https://github.com/rdimitrov/go-tuf-metadata.

It includes the following changes:

• [x] Created a commit which wiped out the existing content
• [x] Cherry-picked all commits from https://github.com/rdimitrov/go-tuf-metadata on top. The motivation is so we can preserve the history of both projects and also recognise the contributions made by all so far.
• [x] Switched rdimitrov/go-tuf-metadata to github.com/theupdateframework/go-tuf/v2
• [ ] Update the licensing to one that corresponds to the theupdateframework organisation (decided to make this in a follow up PR so we keep this one only about the migration)

What's next

• Once we merge this, we'll leave some time (more than a month) before we deprecate the rdimitrov/go-tuf-metadata repository in favour of this one
• Migrate all opened issues to this repository and revisit existing ones whether they still make sense or not
• Migrate back things that are useful from the legacy go-tuf code - templates, code owner files, licence files, workflows?, etc.

Motivated by https://github.com/theupdateframework/go-tuf/issues/485

Types of changes:

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause existing functionality to not work as expected). Please ensure that your PR title is a Conventional Commit breaking change (with a !, as in feat!: change foo).

Description of the changes being introduced by the pull request:

Please verify and check that the pull request fulfills the following requirements:

• [ ] Tests have been added for the bug fix or new feature
• [ ] Docs have been added for the bug fix or new feature

[rdimitrov]

This is what I used to copy the content and its history -

#!/bin/bash

# Retrieve all commit hashes from the first commit onwards, in chronological order
commit_hashes=$(git log source/main --reverse --format="%H")

# Cherry-pick each commit from the source repository
for commit in $commit_hashes; do
    git cherry-pick $commit
    if [ $? -ne 0 ]; then
        echo "Cherry-picking commit $commit failed."
    fi
done
echo "All commits have been successfully cherry-picked"

• There were 3 merge commits (empty) that failed being cherry-picked but since they are empty ones they are not relevant
• source/main is rdimitrov/go-tuf-metadata@main

[kommendorkapten]

So excited to see this! 🚀