Add --typePrefixStrip for stripping a prefix from type and enum member names

[tannergooding]

Adds a new --typePrefixStrip (-tp) value option, the type-side analog of the existing --prefixStrip for methods. It strips a library-wide prefix from enum/struct/union type names, at both the declaration and every reference, reusing the existing PrefixAndStrip plumbing rather than adding a parallel path. It also strips the prefix from enum member names and composes with --config strip-enum-member-type-name.

Given:

typedef struct abc_some_struct { int value; } abc_some_struct;
typedef enum abc_some_enum { abc_some_enum_key1, abc_some_enum_key2 } abc_some_enum;
typedef struct abc_2d_point { int x; int y; } abc_2d_point;
void abc_use(abc_some_struct* s, abc_some_enum e, abc_2d_point* p);

with --typePrefixStrip abc_:

public partial struct some_struct { public int value; }
public enum some_enum { some_enum_key1, some_enum_key2 }
public partial struct _2d_point { public int x; public int y; }
public static extern void abc_use(some_struct* s, some_enum e, _2d_point* p);

Adding --config strip-enum-member-type-name collapses the members further to key1/key2 (the library prefix is stripped first, then the already-stripped enum type name).

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The stripping is applied at the two consistent tag-type naming choke points -- GetRemappedCursorName for declarations and ApplyTagTypeNameOverrides for references -- plus EscapeAndStripEnumMemberName for members, so declarations and every reference resolve to the same C# name.

Edge cases:

• A result that would leave a leading digit keeps an underscore (abc_2d_point -> _2d_point) so it stays a valid C# identifier.
• An empty result (the name was exactly the prefix) is skipped, keeping the original name.
• An explicit --remap/--remap-type always wins over stripping.
• NativeTypeName attributes and the EntryPoint/mangled name keep the original C spelling.
• Collisions that result from stripping are the user''s responsibility and can be resolved with an explicit --remap.

This is the explicit-prefix form only; auto-detecting a non-obvious common prefix (or a common postfix) per enum is intentionally left out and can be a follow-up. As a reminder, one of the best existing ways to consume these is simply using static abc_some_enum;, after which abc_some_enum_key1 works unqualified.

Addresses #333 and #461.

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Build is clean (0 warnings) and dotnet test -c Release passes (3772 passed, 0 failed). Adds TypePrefixStripTest with golden baselines covering both the types-only and combined cases.