feat(java): add float support

[mengnankkkk]

Why?

What does this PR do?

Related issues

Close #3205

Does this PR introduce any user-facing change?

• Does this PR introduce any public API change?
• Does this PR introduce any binary protocol compatibility change?

Benchmark

[chaokunyang]

Could you also address those issues?

1. XLANG support for new Float16 types is broken at runtime.
   Float16/Float16List serializers are added (PrimitiveSerializers.java, PrimitiveListSerializers.java), but internal xlang type registration is missing in resolver bootstrap (ClassResolver.java). In xlang mode it falls back to unsupported-class path and fails at deserialize time.

   • java/fory-core/src/main/java/org/apache/fory/serializer/PrimitiveSerializers.java:381
   • java/fory-core/src/main/java/org/apache/fory/serializer/collection/PrimitiveListSerializers.java:595
   • java/fory-core/src/main/java/org/apache/fory/resolver/ClassResolver.java:262
   • java/fory-core/src/main/java/org/apache/fory/resolver/ClassResolver.java:295
   • java/fory-core/src/main/java/org/apache/fory/resolver/ClassResolver.java:1305

2. Float16 subnormal decode is numerically wrong.
   In float16BitsToFloat, subnormal conversion uses an incorrect shift/exponent formula.

   • java/fory-core/src/main/java/org/apache/fory/type/Float16.java:169
   • java/fory-core/src/main/java/org/apache/fory/type/Float16.java:173
     Repro: Float16.fromBits((short)0x0001).floatValue() returns 1.7881393E-7, expected 5.9604645E-8 (2^-24).

3. Float16[] serializer crashes on legal arrays containing null.
   The array fast path dereferences element directly (value[i].toBits()), so new Float16[]{Float16.ONE, null} throws NPE.

   • java/fory-core/src/main/java/org/apache/fory/serializer/ArraySerializers.java:901

4. Type-id mapping regression for existing float kinds.
   Types.getClassForTypeId now maps FLOAT8 to Float16, and BFLOAT16 mapping was removed (falls through to null).

   • java/fory-core/src/main/java/org/apache/fory/type/Types.java:450
   • java/fory-core/src/main/java/org/apache/fory/type/Types.java:452

5. Generated Java equals/hashCode contract can break for float16.
   Generator uses equalsValue for FLOAT16 equality, but default hash path remains Objects.hash(...). equalsValue treats +0 and -0 as equal, while Float16.hashCode is bit-based.

   • compiler/fory_compiler/generators/java.py:1384
   • compiler/fory_compiler/generators/java.py:1467
   • java/fory-core/src/main/java/org/apache/fory/type/Float16.java:270
   • java/fory-core/src/main/java/org/apache/fory/type/Float16.java:334

[chaokunyang]

remove it, we don' have xwrite/xread methods any more