refactor(pprocessor): rename macro table type and update function names

- Change `scc_macro_table_t` to `scc_pp_macro_table_t` for consistency
- Rename `scc_pp_macro_create` to `scc_pp_macro_new` for naming convention
- Remove unused `scc_pp_compress_whitespace` function
- Update macro table function names: `scc_pp_find_macro` → `scc_pp_macro_table_get`, `scc_pp_remove_macro` → `scc_pp_macro_table_remove`
- Add new `scc_pp_macro_table_set` function for setting macros
- Update all function signatures to use new type name
- Remove commented-out whitespace compression code from implementation

libs/pprocessor/include/pprocessor.h

@@ -28,7 +28,7 @@ typedef struct if_stack_item {
 typedef struct scc_pproc {
     scc_probe_stream_t *stream; // 输出流
     scc_strpool_t strpool;      // 字符串池
-    scc_macro_table_t macro_table;
+    scc_pp_macro_table_t macro_table;
     SCC_VEC(if_stack_item_t) if_stack; // 条件编译栈
 } scc_pproc_t;