[Backport 2.x] Notification security fix (#861)

[stevanbz]

• Notification security fix (Notification security fix #852)

• added injecting whole user object in threadContext before calling notification APIs so that backend roles are available to notification plugin

• compile fix

• refactored user_info injection to use InjectSecurity

• ktlint fix

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(cherry picked from commit e0b7a5a)

• remove unneeded import

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Issue #, if available:

Description of changes:

CheckList:
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[opensearch-trigger-bot]

The backport to 2.5 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-2.5 2.5
# Navigate to the new working tree
cd .worktrees/backport-2.5
# Create a new branch
git switch --create backport/backport-863-to-2.5
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 264a4476be49ce4981daa29b44e5cc02dfa029f0
# Push it to GitHub
git push --set-upstream origin backport/backport-863-to-2.5
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-2.5

Then, create a pull request where the base branch is 2.5 and the compare/head branch is backport/backport-863-to-2.5.

[opensearch-trigger-bot]

The backport to 2.3 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-2.3 2.3
# Navigate to the new working tree
cd .worktrees/backport-2.3
# Create a new branch
git switch --create backport/backport-863-to-2.3
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 264a4476be49ce4981daa29b44e5cc02dfa029f0
# Push it to GitHub
git push --set-upstream origin backport/backport-863-to-2.3
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-2.3

Then, create a pull request where the base branch is 2.3 and the compare/head branch is backport/backport-863-to-2.3.