Skip call price checks after callability parameter removal

[caydyan]

Summary

• add a new issuance_callable_lock_fix protocol change at the current 11.1.0 activation batch
• gate the relaxed callable/call date/call price reissuance checks behind that future activation
• cover pre-activation, post-activation, and disabled-gate behavior for the old callable asset case

Context

This is a develop-based replacement for the earlier master PR:

• Supersedes: Skip call price checks after callability parameter removal #3340
• Related issue: Cannot lock callable asset #1338

The earlier review confirmed the bug but requested a new future protocol gate to avoid a retroactive consensus change. This version keeps that gate and the activation boundary test on current develop.

Verification

• /Users/cayd/Documents/btc/work/counterparty-core/counterparty-core/.venv/bin/python -m pytest counterpartycore/test/units/messages/issuance_test.py::test_validate -q
• /Users/cayd/Documents/btc/work/counterparty-core/counterparty-core/.venv/bin/python -m pytest counterpartycore/test/units/messages/issuance_test.py -q
• /Users/cayd/Documents/btc/work/counterparty-core/counterparty-core/.venv/bin/python -m ruff check counterpartycore/lib/messages/issuance.py counterpartycore/test/units/messages/issuance_test.py
• /Users/cayd/Documents/btc/work/counterparty-core/counterparty-core/.venv/bin/python -m ruff format --check counterpartycore/lib/messages/issuance.py counterpartycore/test/units/messages/issuance_test.py
• /Users/cayd/Documents/btc/work/counterparty-core/counterparty-core/.venv/bin/python -m json.tool counterpartycore/protocol_changes.json
• git diff --check

Payout

If this qualifies for a contributor or bug-fix reward, please send BTC to:

bc1qev5ant33v5y89qqjvcf4mh9hlax5svqf5xd7gc