[15.0][MIG] currency_rate_update_wise

[klodr]

currency_rate_update_wise → 15.0

Forward-port of the Wise.com exchange-rate provider from 14.0 to 15.0.
Framework migration only, no functional change.

Notes for reviewers

• Hermetic tests: the Wise HTTP layer (_wise_provider_retrieve) is mocked —
  no network access needed in CI.
• Carries a small, non-blocking helper that logs a warning when the configured
  API token still uses the legacy UUID format (Wise UUID → JWT migration).

[klodr]

A note on the red CI, for reviewers:

• pre-commit fails because the setuptools-odoo 3.1.8 hooks import the removed pkg_resources; this is fixed by the prerequisite bump [15.0] pre-commit: bump setuptools-odoo to 3.3.2 #226.
• test with OCB / test with Odoo fail solely on the pre-existing currency_rate_update_xe module — its test_cron / test_wizard make real network calls to xe.com (which no longer returns usable data), asserting 0 != 1. This is unrelated to this PR.

currency_rate_update_wise itself installs cleanly and all 10 of its tests pass — the Wise HTTP layer is mocked, so no network access is needed in CI. The xe.com test issue is addressed on the other branches in #216 (16.0) / #218 (17.0) / #220 (14.0).