Convert software submission to an issue form

[eliotwrobson]

Summary

• convert the software submission template from Markdown to a GitHub Issue Form
• preserve the current submission questions in structured fields and required checkboxes
• update the pycmdcheck triage workflow parser to accept both legacy Field: value lines and Issue Form ### Field sections

Why This Is Separate

This PR is intentionally stacked on top of #309 because the parser change depends on the triage workflow added there. Keeping it separate allows the issue form conversion to be reviewed independently.

What Changes

• replace .github/ISSUE_TEMPLATE/submit-software-for-review.md with .github/ISSUE_TEMPLATE/submit-software-for-review.yml
• keep the submission fields needed by automation, including Package Name, Repository Link, and Version submitted
• keep editorial tracking placeholders in the submitted issue body
• make the workflow parser backward compatible during the transition

Validation

• validated the new Issue Form file in the editor with no YAML errors
• validated the updated workflow file in the editor with no YAML errors
• confirmed the old Markdown submission template is no longer present in .github/ISSUE_TEMPLATE