Rename setterSuffix option: it is applied as a prefix, not a suffix #342

Problem

The configuration option setterSuffix is misleadingly named: it is applied as a prefix, not a suffix.

MethodGeneratorUtil.generateBuilderMethodName produces setterSuffix + capitalize(fieldName), so setterSuffix = "with" generates withName(...), withNameUpdate(...) — never nameWith(...).

The documentation already describes prefix semantics ("Adds a prefix to all setter method names", -Asimplebuilder.setterSuffix=customPrefix), so only the option name is wrong — but it is confusing enough that it caused a real bug in #312, where the MapStruct naming strategy initially derived <field><suffix> names that could never match a generated setter.

Where the name appears

• @SimpleBuilder.Options#setterSuffix() (annotation element)
• BuilderConfiguration.Builder#setterSuffix / BuilderConfiguration#getSetterSuffix()
• Compiler argument -Asimplebuilder.setterSuffix (CompilerArgumentsEnum.SETTER_SUFFIX)
• docs/CONFIGURATION.md and generated javadoc

Decision (per maintainer)

Hard rename — no compatibility alias. The project has not hit 1.0, so the clean break is acceptable: existing user configs fail loudly on the unknown option rather than silently changing behaviour later.

Proposal

Rename the option to setterPrefix across annotation element, configuration API, compiler argument (-Asimplebuilder.setterPrefix) and docs, removing setterSuffix entirely.

Surfaced in #312 (MapStruct integration, fixes #300).