Standardize naming conventions (#12)

## Summary

Standardize naming conventions across the entire wizapp-stdlib codebase by replacing inconsistent prefixes and snake_case with a unified `wp` prefix + CamelCase scheme.

## Changes

### Naming convention applied

| Pattern | Before | After |
|---|---|---|
| Public functions | `wapp_module_function` | `wpModuleFunction` |
| Public types | `GenericXxx`, bare `Xxx` | `WpXxx` |
| Constants / enum values | `WAPP_XXX`, `SHELL_XXX` | `WP_XXX`, `WP_SHELL_XXX` |
| Internal functions | `_module_function` | `_moduleFunction` |
| Storage-class macros | `wapp_extern`, `wapp_intern` | `wp_extern`, `wp_intern` |

### Modules affected

All 20 modules were renamed: `arena`, `array`, `dbl_list`, `queue`, `str8`, `mem_allocator`, `mem_utils`, `mem_os`, `file`, `cpath`, `log`, `shell_commander`, `shell_termcolour`, `shell_utils`, `prng/xorshift`, `uuid`, `tester`, `aliases`, `assert`, `misc_utils`, `platform` — plus their test files.

### Backward compatibility

Added `src/oldnames.h` with `#define OLD_NAME NEW_NAME` for every renamed symbol, organized by module under Constants → Types → Functions sections. Existing code that includes this file will compile without changes.

Reviewed-on: #12
Co-authored-by: Abdelrahman <said.abdelrahman89@gmail.com>
Co-committed-by: Abdelrahman <said.abdelrahman89@gmail.com>

tests/str8/test_str8.h

@@ -3,31 +3,31 @@
 
 #include "wapp.h"
 
-TestFuncResult test_str8_lit(void);
-TestFuncResult test_str8_lit_ro(void);
-TestFuncResult test_str8_buf(void);
-TestFuncResult test_str8_alloc_buf(void);
-TestFuncResult test_str8_alloc_cstr(void);
-TestFuncResult test_str8_alloc_str8(void);
-TestFuncResult test_str8_alloc_substr(void);
-TestFuncResult test_str8_alloc_concat(void);
-TestFuncResult test_str8_get_index_within_bounds(void);
-TestFuncResult test_str8_get_index_out_of_bounds(void);
-TestFuncResult test_str8_set(void);
-TestFuncResult test_str8_push_back(void);
-TestFuncResult test_str8_equal(void);
-TestFuncResult test_str8_slice(void);
-TestFuncResult test_str8_concat_capped(void);
-TestFuncResult test_str8_copy_cstr_capped(void);
-TestFuncResult test_str8_copy_str8_capped(void);
-TestFuncResult test_str8_format(void);
-TestFuncResult test_str8_find(void);
-TestFuncResult test_str8_rfind(void);
-TestFuncResult test_str8_split(void);
-TestFuncResult test_str8_split_with_max(void);
-TestFuncResult test_str8_rsplit(void);
-TestFuncResult test_str8_rsplit_with_max(void);
-TestFuncResult test_str8_join(void);
-TestFuncResult test_str8_from_bytes(void);
+WpTestFuncResult test_str8_lit(void);
+WpTestFuncResult test_str8_lit_ro(void);
+WpTestFuncResult test_str8_buf(void);
+WpTestFuncResult test_str8_alloc_buf(void);
+WpTestFuncResult test_str8_alloc_cstr(void);
+WpTestFuncResult test_str8_alloc_str8(void);
+WpTestFuncResult test_str8_alloc_substr(void);
+WpTestFuncResult test_str8_alloc_concat(void);
+WpTestFuncResult test_str8_get_index_within_bounds(void);
+WpTestFuncResult test_str8_get_index_out_of_bounds(void);
+WpTestFuncResult test_str8_set(void);
+WpTestFuncResult test_str8_push_back(void);
+WpTestFuncResult test_str8_equal(void);
+WpTestFuncResult test_str8_slice(void);
+WpTestFuncResult test_str8_concat_capped(void);
+WpTestFuncResult test_str8_copy_cstr_capped(void);
+WpTestFuncResult test_str8_copy_str8_capped(void);
+WpTestFuncResult test_str8_format(void);
+WpTestFuncResult test_str8_find(void);
+WpTestFuncResult test_str8_rfind(void);
+WpTestFuncResult test_str8_split(void);
+WpTestFuncResult test_str8_split_with_max(void);
+WpTestFuncResult test_str8_rsplit(void);
+WpTestFuncResult test_str8_rsplit_with_max(void);
+WpTestFuncResult test_str8_join(void);
+WpTestFuncResult test_str8_from_bytes(void);
 
 #endif // !TEST_STR8_H