Backport #11924: Fix slashing migration to v10

[chevdor]

Backport of #11924 to the 0.9.27 release branch

• Fix slashing migration to v10

• add some logs

• Fix default version

• fmt

• Move doc to struct

Co-authored-by: Wilfried Kopp [email protected]

✄ -----------------------------------------------------------------------------

Thank you for your Pull Request! 🙏

Before you submit, please check that:

• Description: You added a brief description of the PR, e.g.:
  • What does it do?
  • What important points should reviewers know?
  • Is there something left for follow-up PRs?
• Labels: You labeled the PR appropriately if you have permissions to do so:
  • A* for PR status (one required)
  • B* for changelog (one required)
  • C* for release notes (exactly one required)
  • D* for various implications/requirements
  • Github project assignment
• Related Issues: You mentioned a related issue if this PR is related to it, e.g. Fixes #228 or Related #1337.
• 2 Reviewers: You asked at least two reviewers to review. If you aren't sure, start with GH suggestions.
• Style Guide: Your PR adheres to the style guide
  • In particular, mind the maximal line length of 100 (120 in exceptional circumstances).
  • There is no commented code checked in unless necessary.
  • Any panickers in the runtime have a proof or were removed.
• Runtime Version: You bumped the runtime version if there are breaking changes in the runtime.
• Docs: You updated any rustdocs which may need to change.
• Polkadot Companion: Has the PR altered the external API or interfaces used by Polkadot?
  • If so, do you have the corresponding Polkadot PR ready?
  • Optionally: Do you have a corresponding Cumulus PR?

Refer to the contributing guide for details.

After you've read this notice feel free to remove it.
Thank you!

✄ -----------------------------------------------------------------------------