Enable issue comment invocation for clang-tidy-check workflow

[greenc-FNAL]

This commit enhances the clang-tidy-check workflow to support on-demand
invocation via issue comments using '@phlexbot tidy-check', providing
developers with a convenient way to run clang-tidy checks without
waiting for automatic PR triggers.

Changes:

• Add issue_comment trigger with authorization check restricting access
  to OWNER, COLLABORATOR, and MEMBER roles following established
  security patterns from clang-tidy-fix workflow

• Integrate get-pr-info action in pre-check job to extract PR details
  (ref, repo, base SHA, PR number) from issue comment events

• Update permissions to include pull-requests: write for posting
  comments on PRs

• Enhance clang-tidy-pr-comments job to support both pull_request and
  issue_comment event types with proper PR number resolution

• Add summary comment when triggered via issue comment that includes:

  • Total count of issues found
  • Breakdown of issues by check type sorted by frequency
  • Reference to inline comments for details
  • Suggestion to use '@phlexbot tidy-fix' for auto-fixing

The workflow now supports three invocation methods:

1. Automatic execution on pull requests
2. Manual execution via workflow_dispatch
3. On-demand execution via '@phlexbot tidy-check' comment on PRs

This provides developers with flexibility to run clang-tidy checks
on-demand while maintaining existing automatic PR checking behavior.

[Copilot]

Pull request overview

Adds an on-demand invocation path for the existing clang-tidy check workflow so developers can trigger it from PR comments (in addition to the existing pull_request and workflow_dispatch triggers).

Changes:

• Add issue_comment trigger with an authorization gate and command parsing for @…bot tidy-check
• Use the get-pr-info action to resolve PR checkout info (ref/repo/base SHA) when triggered by comments
• Extend the comment-posting job to work for both pull_request and issue_comment events and add a summarized results comment