chore: Improve log and comment messages

#### Motivation and Context - Issue-type log entries can be misleading. https://github.com/ScoopInstaller/GithubActions/blob/ff4a9f14fcb4dab64865355a75d3f6139b1884b8/src/Action/Issue.psm1#L219-L234 e.g. Closes #52 - Lack of clear instructions to lead contributors to re-run the PR checks when failed. #### Description This PR makes the following changes: - chore: Improve log and comment messages. <!-- This is an auto-generated comment: release notes by coderabbit.ai --> ## Summary by CodeRabbit * Style * Standardized punctuation and clarified wording in issue messages, making problem types explicit (e.g., hash check, extract directory, download failure). * Replaced vague phrasing with clearer “Unsupported issue type” and included the specific problem in logs. * Refactor * PR failure notice reformatted into a concise three-line block with clearer language. * Added explicit guidance on addressing manifest issues and how to rerun checks via a comment command. * Maintains existing behavior for labels and message posting; no changes to public APIs. <!-- end of auto-generated comment: release notes by coderabbit.ai -->