[DOCS] Renames ML get usage info APIs back to get stats

[szabosteve]

Overview

Closes #4288

This PR renames the GET datafeed, anomaly detection, and data frame analytics usage info APIs to GET stats, as this was the name before switching to the new system.

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
ml.get_data_frame_analytics_stats	🟢	12/12	12/12
ml.get_datafeed_stats	🟢	27/27	27/27
ml.get_job_stats	🟢	32/32	32/32

You can validate these APIs yourself by using the make validate target.

[valeriy42]

LGTM

[github-actions]

The backport to 8.16 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-8.16 8.16
# Navigate to the new working tree
cd .worktrees/backport-8.16
# Create a new branch
git switch --create backport-4299-to-8.16
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 42e9256a5dde9c1bc7e43d96acd8d6dda448cc22
# Push it to GitHub
git push --set-upstream origin backport-4299-to-8.16
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-8.16

Then, create a pull request where the base branch is 8.16 and the compare/head branch is backport-4299-to-8.16.

[github-actions]

The backport to 8.17 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-8.17 8.17
# Navigate to the new working tree
cd .worktrees/backport-8.17
# Create a new branch
git switch --create backport-4299-to-8.17
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 42e9256a5dde9c1bc7e43d96acd8d6dda448cc22
# Push it to GitHub
git push --set-upstream origin backport-4299-to-8.17
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-8.17

Then, create a pull request where the base branch is 8.17 and the compare/head branch is backport-4299-to-8.17.

[github-actions]

The backport to 9.0 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-9.0 9.0
# Navigate to the new working tree
cd .worktrees/backport-9.0
# Create a new branch
git switch --create backport-4299-to-9.0
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 42e9256a5dde9c1bc7e43d96acd8d6dda448cc22
# Push it to GitHub
git push --set-upstream origin backport-4299-to-9.0
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-9.0

Then, create a pull request where the base branch is 9.0 and the compare/head branch is backport-4299-to-9.0.