Add --with-enum-member-strip for per-enum member name stripping

[tannergooding]

Note

This PR body was drafted by Copilot.

Resolves #461 -- adds a single, mode-based option for stripping a common prefix or suffix from an enum's member names, so enum abc_some_enum { abc_some_enum_key1, ... } can generate first/second/... instead of the fully-qualified member names.

--with-enum-member-strip <enum-name>=<mode> (alias -wems) is a per-enum knob keyed by the remapped enum name, reusing the existing with-* dictionary plumbing: * sets a global default and per-enum entries override it. Modes:

• none -- leave the members alone.
• common-prefix -- auto-detect the longest common prefix of the members.
• common-suffix -- same, for the "common POSTfix instead of prefix" case.
• type-name -- strip the enum type name (identical to strip-enum-member-type-name).
• prefix:<str> / suffix:<str> -- strip an explicit string.

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Honored edge cases for the auto-detect modes:

• The detected prefix/suffix is trimmed back to the nearest _ token boundary so a non-obvious prefix never cuts mid-token (abc_some_enum_key1/key2 -> key1/key2, not 1/2).
• A leading digit after stripping is guarded with _ since it isn't a valid C# identifier start (abc_version_1_0 -> _1_0).
• Stripping is all-or-nothing per enum: if any member would become empty or two would collide, the whole enum keeps its original names and an Info diagnostic is emitted naming the enum and the reason, so the member set stays internally consistent.
• The strip is applied identically at the declaration and at every sibling reference in initializer expressions (e.g. primary = vulkan | metal), so the generated bindings still compile.

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This composes with, and falls back to, the existing behavior: when no mode resolves for an enum, the legacy strip-enum-member-type-name / --typePrefixStrip handling runs unchanged. using static <EnumType>; also remains available as a zero-config workaround.

Added golden tests covering common-prefix/-suffix, explicit prefix:/suffix:, the digit guard, single-member no-op, collision abandonment with the diagnostic, type-name matching the legacy behavior, the * default with a per-enum override, and decl/ref consistency for sibling references.