Validate fairminter integer parameters before comparisons

[caydyan]

Supersedes #3389 with the same fix rebased onto the current develop branch.

fairminter.validate() records non-integer numeric parameters such as quantity_by_price, but it continued into numeric comparisons afterward. For example, quantity_by_price="1" is recorded as invalid and then reaches quantity_by_price < 1, raising a Python TypeError instead of returning the compose-level validation error.

This PR stops fairminter validation before numeric comparison logic when any numeric fairminter parameter is not an integer.

Changes:

• Tracks whether any fairminter integer parameter failed type validation.
• Returns those validation errors before later numeric comparisons.
• Adds regression coverage for validate and compose paths.

Tests:

• python -m pytest counterpartycore/test/units/messages/fairminter_test.py::test_validate counterpartycore/test/units/messages/fairminter_test.py::test_compose -q
• python -m pytest counterpartycore/test/units/messages/fairminter_test.py -q
• python -m ruff check counterpartycore/lib/messages/fairminter.py counterpartycore/test/units/messages/fairminter_test.py
• python -m ruff format --check counterpartycore/lib/messages/fairminter.py counterpartycore/test/units/messages/fairminter_test.py
• git diff --check

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