feat(core): rename string and stream functions for clarity

- Rename `cstring_push` to `cstring_append_ch` and `cstring_push_cstr` to `cstring_append_cstr` for consistent naming with new `cstring_append` function
- Update all callers in lexer and tests to use new function names
- Rename stream `destroy` method to `drop` for consistency with resource management conventions
- Fix potential overflow in string capacity calculation by adjusting growth logic

libs/lex_parser/src/lex_parser.c

@@ -293,7 +293,7 @@ cbool lex_parse_string(core_probe_stream_t *input, core_pos_t *pos,
             if (val == -1) {
                 LOG_ERROR("Invalid escape character it is \\%c [%d]", ch, ch);
             } else {
-                cstring_push(&str, val);
+                cstring_append_ch(&str, val);
                 continue;
             }
         } else if (ch == '"') {
@@ -304,7 +304,7 @@ cbool lex_parse_string(core_probe_stream_t *input, core_pos_t *pos,
 
         core_probe_stream_consume(stream);
         core_pos_next(pos);
-        cstring_push(&str, ch);
+        cstring_append_ch(&str, ch);
     }
 
     *output = str;
@@ -419,7 +419,7 @@ cbool lex_parse_identifier(core_probe_stream_t *input, core_pos_t *pos,
     } else if (ch == '_' || (ch >= 'a' && ch <= 'z') ||
                (ch >= 'A' && ch <= 'Z')) {
         while (1) {
-            cstring_push(output, ch);
+            cstring_append_ch(output, ch);
             core_probe_stream_consume(stream);
             core_pos_next(pos);
             ch = core_probe_stream_peek(stream);