Summary of PR #7510: Obsolete old saga mapping API

[Copilot]

This is a summary of the changes in #7510, which obsoletes the old saga mapping API in favor of the MapSaga() fluent syntax.

Breaking Change

The old ConfigureMapping<T>().ToSaga() pattern is now a compile-time error. Use MapSaga().ToMessage<T>() instead.

Before:

mapper.ConfigureMapping<Msg>(m => m.OrderId).ToSaga(s => s.OrderId);
mapper.ConfigureHeaderMapping<Msg>("Header").ToSaga(s => s.OrderId);

After:

mapper.MapSaga(s => s.OrderId)
    .ToMessage<Msg>(m => m.OrderId)
    .ToMessageHeader<Msg>("Header");

Changes

• Obsoleted APIs (error: true): ConfigureMapping<T>(), ConfigureHeaderMapping<T>(), IToSagaExpression<T>, ToSagaExpression<T,M>
• Removed: RewriteConfigureHowToFindSagaFixer.cs, NSB0018 diagnostic, old syntax parsing in SagaAnalyzer
• Removed internal types: ToSagaExpression.cs, IToSagaExpression.cs, MessageHeaderToSagaExpression.cs
• Updated: All saga tests (52 files) converted to new syntax

Stats

+370/-1,862 lines across 52 files. Labeled as breaking change, targeted at vNext milestone.

Original prompt

Summarize changes in #7510

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