Add explicit stop method to Auditable

[stevejgordon]

Resolves #5363

Allows consumers of Auditable to explicitly call Stop to set the ended DateTime on the Audit object. This ensures that by the time this is available in a DiagnosticsListener Audit has a valid end DateTime set. Otherwise, it is the default until the Auditable is disposed.

[Mpdreamz]

LGTM, do we want this to be called multiple times to override or not?

I think its fine as is.

[github-actions]

The backport to master failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-master master
# Navigate to the new working tree
cd .worktrees/backport-master
# Create a new branch
git switch --create backport-5413-to-master
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick ---mainline 1 9cc8548439d3a9a0e4c3f54f128e99287002c143
# Push it to GitHub
git push --set-upstream origin backport-5413-to-master
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-master

Then, create a pull request where the base branch is master and the compare/head branch is backport-5413-to-master.