10.x: read a YearMonthRange upper bound in a query as the first day of its month (port of #506) #511

Problem

On main, PR #509 makes a query read a YearMonthRange upper bound as the first day of its month (#506). On release/10.x, UpperBound() and Clamp still read the last day. So in a filter, UpperBound() == month is false and > month is true for a range ending in that month.

Change

Cherry-pick PR #509's commits with -x into a PR against release/10.x: CoarseUpperBound and its YearMonth registration, CoarseUpper, the ClampDomainParityTests comparisons, YearMonthBoundParityTests, the infinity-disabled test, the translation asserts, the oracle, both seeds and claim E88.

• 10.x specifics: the changelog row goes under ### Changed answers in [10.4.0] (root and EF Core NodaTime), linking this issue and #changed-answers-in-1040. docs/migration.md gets Check YearMonthRange upper bounds compared in queries under ## Changed answers in 10.4.0. pr-hygiene.sh requires both for a silent PR into a minor.

Done when

On release/10.x, the tests pass on the EF Core 10.0.0 floor and on CI's newest-patch leg, they fail with the fix reverted, and both seeds are caught.

Release

### Changed answers in 10.4.0. Fixed only on release/10.x, so close it by hand.