feat: add --status filter to gitt issues list

[jakearmstrong59]

Summary

Adds a --status filter to gitt issues list so users can list only issues in a specific lifecycle state:

​bash gitt issues list --status active gitt issues list --status registered gitt issues list --status completed gitt issues list --status cancelled ​

Closes #1473

Changes

• New STATUS_CHOICE click constant in issue_commands/helpers.py, alongside the existing NETWORK_CHOICE, covering the four on-chain statuses.
• New --status option on issues list, mirroring the existing --repo filter (feat: add --repo filter to gitt issues list #910): a client-side, case-insensitive filter applied identically to both the table view and --json output, with --id taking precedence.
• Behavior is unchanged when the flag is omitted; unknown values are rejected at parse time by click.Choice.
• Two tests in tests/cli/test_issues_list_json.py: JSON filtering with case-insensitive input, and parse-time rejection of invalid values (no contract read).

Testing

• uv run pytest tests/ — 919 passed
• uv run pre-commit run --all-files (ruff lint/format) and pre-push hooks (pyright, vulture) — all green
• Manually exercised table + JSON paths, --status combined with --repo, --id precedence, and no-match output via CliRunner